• upgrade to Win10 in dual boot environment

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    #503265

    i’ve got a laptop with dual boot set up between Windows Vista and Windows 8.1. i’d like to upgrade the 8.1 partition to 10, but i want to keep the dual boot with Vista — IOW, have the dual boot now be between Vista and 10.

    will the Win10 upgrade to the 8.1 partition leave my dual boot setup as is, or is it going to screw that up? i would think this should work fine, but every time i make an assumption about Microsoft, i end up paying dearly for it. πŸ™

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    • #1538542

      Windows 10 should recognize the dual boot and keep it intact.

      Always create a fresh drive image before making system changes/Windows updates; you may need to start over!
      We were all once "Average Users". We all have our own reasons for doing the things that we do with our systems, we don't need anyone's approval, and we don't all have to do the same things.

    • #1538645

      … every time i make an assumption about Microsoft, i end up paying dearly for it. πŸ™

      You think ??? :rolleyes:

      A disk image saved before you do anything else may save your bacon.

      If after the upgrade to Win10, its bootmenu doesn’t see Vista any more, EasyBCD[/url] will probably get it back.

      Something similar happened to me with firstly Win7/32 + secondly Win10/64 in dual boot.
      EasyBCD put the dropped Win7 entry back in my bootmenu.

    • #1538672

      thanks for the info on EasyBCD — looks like a very useful tool, and particularly in this case if things go bonkers.

      and yeah, most definitely will be imaging the drive before i venture down this road.

    • #1538735

      lhite,

      I upgraded my dual boot Dell laptop using EasyBCD to Win 10 ISO from the Media Creation Tool. Worked like a charm. Of course I had a complete Macrium Reflect Image of the drive before attempting this. HTH :cheers:

      May the Forces of good computing be with you!

      RG

      PowerShell & VBA Rule!
      Computer Specs

      • #1538744

        lhite,

        I upgraded my dual boot Dell laptop using EasyBCD to Win 10 ISO from the Media Creation Tool. Worked like a charm. Of course I had a complete Macrium Reflect Image of the drive before attempting this. HTH :cheers:

        Does that mean you are booting the Iso? If so what boot manager are you using?

        :cheers:

        🍻

        Just because you don't know where you are going doesn't mean any road will get you there.
    • #1538747

      David,

      No, sorry for the confusion, I installed from the ISO vs Windows Update. I’m using EasyBCD as my boot manager. HTH :cheers:

      May the Forces of good computing be with you!

      RG

      PowerShell & VBA Rule!
      Computer Specs

    • #1538769

      Ok I can be a bit dense at times too!
      πŸ˜‰
      :cheers:

      🍻

      Just because you don't know where you are going doesn't mean any road will get you there.
    • #1538778

      I’m still using the Windows 7 bootmgr. Windows 8/8.1 and 10 bootmgr partially load the default OS before presenting the boot menu; choose the non-default OS and it requires a complete reboot, a needless delay.

      The Windows 7 bootmgr presents the boot menu first, eliminating that boot delay.

      Always create a fresh drive image before making system changes/Windows updates; you may need to start over!
      We were all once "Average Users". We all have our own reasons for doing the things that we do with our systems, we don't need anyone's approval, and we don't all have to do the same things.

      • #1539536

        finally got around to doing the upgrade, and sure enough my dual boot was left intact, just as i had wanted it, just as everyone here said it would. thanks!

      • #1539728

        … Windows 8/8.1 and 10 bootmgr partially load the default OS before presenting the boot menu; choose the non-default OS and it requires a complete reboot, a needless delay.

        I think that’s because you’re using Win10’s ”hybrid shut down”.
        With this feature enabled, Win10 partially hibernates instead of fully shutting down. Win10 calls it ”fast start-up”.

        What you describe won’t happen if that feature is disabled.

        The switch to turn hybrid shutdown ON/OFF is in
        Settings / Power & sleep / Additional power settings /Choose what the power buttons do / Turn on fast start-up (recommended)

        • #1539736

          I think that’s because you’re using Win10’s ”hybrid shut down”.
          With this feature enabled, Win10 partially hibernates instead of fully shutting down. Win10 calls it ”fast start-up”.

          What you describe won’t happen if that feature is disabled.

          I’ve never used that “feature”, disabled it as well as hibernation on my desktops on first boot after upgrading to Windows 8 and again to Windows 10.

          What I describe won’t happen using the Windows 7 bootmgr, but it will happen with the Windows 8 and Windows 10 bootmgr in a dual boot setup.

          Trust me.

          Windows 8 bootmgr

          Windows 7 bootmgr

          Always create a fresh drive image before making system changes/Windows updates; you may need to start over!
          We were all once "Average Users". We all have our own reasons for doing the things that we do with our systems, we don't need anyone's approval, and we don't all have to do the same things.

          • #1539742


            What I describe won’t happen using the Windows 7 bootmgr, but it will happen with the Windows 8 and Windows 10 bootmgr in a dual boot setup.

            Trust me.

            Windows 8 bootmgr

            Windows 7 bootmgr

            Hm, I’m confused.

            In october I repartitioned my system SSD, which restored my PC to its brandnew (Febr 2015) and virginal condition, or almost anyway. Then:

            1. I clean installed Win7/32 to the *4th* partition.

            2. The boot manager showed 1 entry: Win7.

            3. I clean installed Win10/64 to the *1st* partition and as default OS.

            4. The boot manager still showed only 1 entry: but now it was Win10.

            5. Win10 running, I coaxed EasyBCD to put the Win7 entry back in the boot manager as secondary OS.

            6. After shutting down from Win10 with fast start OFF, the PC behaves like in your Windows 7 bootmgr video.

            7. After shutting down from Win10 with fast start ON, the PC behaves like in your Windows 8 bootmgr video.

            So finally, which boot manager am I running? 7 or 10? :confused:

            I would say 10 because Win10 was installed after Win7, but you made me doubt my sanity. :huh:

            • #1539774

              So finally, which boot manager am I running? 7 or 10? :confused:

              I would say 10 because Win10 was installed after Win7, but you made me doubt my sanity. :huh:

              Which video does it look like? The Windows 7 bootmgr is CUI only, and the Windows 10 bootmgr defaults to GUI. Do you see the circling marbles? If so, it’s not the Windows 7 bootmgr.

              Also bear in mind that while bootmgr uses the BCD Store, it isn’t part of the BCD Store. Bootmgr reads the boot menu from the BCD Store and offers it up at boot, then acts on the selection made. In addition, the behavior is a bit different between BIOS/MBR and UEFI/GPT systems. Is your system UEFI?

              That’s why I ask which video does it look like. The Windows 7 bootmgr will be white letters on a black screen. Also, the reboot only occurs if one chooses to load the non-default OS; choosing the default OS will not require a reboot.

              Always create a fresh drive image before making system changes/Windows updates; you may need to start over!
              We were all once "Average Users". We all have our own reasons for doing the things that we do with our systems, we don't need anyone's approval, and we don't all have to do the same things.

            • #1540062

              … Do you see the circling marbles? If so, it’s not the Windows 7 bootmgr. … The Windows 7 bootmgr will be white letters on a black screen. …

              As nobody else will ever access my computer – while I’m alive, that is – I configured it for BIOS/MBR boot. Win10 is default OS.

              With fast start ON the monitor shows at power up:
              1. the computer dealer’s splash screen (no owlish head), + the message Resuming from hibernation, all white on black, and NO setup or boot order options,
              2. the Win10 logo, light blue on black, and the ring of tail chasing marbles, white on black,
              3. the Win10/Win7 boot options, light blue graphics on darker blue, like in your bootmgr 8 clip, and further on the same behavior and looks, i.e. it reboots on Win7 choice.

              With fast start OFF it shows:
              1. the computer dealer’s splash screen + the setup and boot order options, white on black
              2. the Windows boot manager menu with 2 boot options, white letters on a black screen, no marble circles appeared yet,
              3. from there on it proceeds directly to the chosen option (no reboots either way), marbles for Win10, animated logo for Win7.

              Still confused … :huh:

            • #1540114

              Do you have an EFI partition by chance?
              42797-Untitled

              :cheers:

              🍻

              Just because you don't know where you are going doesn't mean any road will get you there.
            • #1540117

              Resuming from hibernation is not a reboot. It is reviving the OS that is already booted.

              Always create a fresh drive image before making system changes/Windows updates; you may need to start over!
              We were all once "Average Users". We all have our own reasons for doing the things that we do with our systems, we don't need anyone's approval, and we don't all have to do the same things.

            • #1540133

              Resuming from hibernation is not a reboot. It is reviving the OS that is already booted.

              Yup but I am unable to explain what exactly is happening and why.
              :confused:

              :cheers:

              🍻

              Just because you don't know where you are going doesn't mean any road will get you there.
            • #1540171

              Yup but I am unable to explain what exactly is happening and why.
              :confused:

              With”fastboot” on, the PC remains in the Windows 10 environment, and is not completely powered down. It is in a low power state, not “off”. With a PC in BIOS/MBR the BCD store is on the boot drive, and resuming from hibernation simply calls the “resume object” from the BCD store via the hibernation API. It looks like Windows 10 because it’s still running in Windows 10.

              Apparently it is using Windows 7 bootmgr based on the cold start behavior.

              Always create a fresh drive image before making system changes/Windows updates; you may need to start over!
              We were all once "Average Users". We all have our own reasons for doing the things that we do with our systems, we don't need anyone's approval, and we don't all have to do the same things.

            • #1540203

              With”fastboot” on, the PC remains in the Windows 10 environment, and is not completely powered down. It is in a low power state, not “off”.

              I don’t think that part is true. Fast startup follows a complete power-off shutdown.

            • #1540242

              I don’t think that part is true. Fast startup follows a complete power-off shutdown.

              Not according to this MSDN article:

              HibernateS4 — The system appears to be off. Power consumption is reduced to the lowest level. The system saves the contents of volatile memory to a hibernation file to preserve system state. Some components remain powered so the computer can wake from input from the keyboard, LAN, or a USB device. The working context can be restored if it is stored on nonvolatile media.

              Fast startup is where the user is logged off before the hibernation file is created. This allows for a smaller hibernation file, more appropriate for systems with less storage capabilities.”

              Soft OffS5 — The system appears to be off. This state is comprised of a full shutdown and boot cycle.”

              Mechanical OffG3 — The system is completely off and consumes no power. The system returns to the working state only after a full reboot.”

              Fast startup in Windows 10 uses Power Level S4, a logged-off-user hibernation file where the contents of volatile memory that are stored in the hibernation file are in a Windows 10 system state. Fast startup awakens that Windows 10 system state, and the user logs on in Windows 10.

              It is not a full shutdown. There is more involved than a “Soft Off” or a “Mechanical Off.”

              Always create a fresh drive image before making system changes/Windows updates; you may need to start over!
              We were all once "Average Users". We all have our own reasons for doing the things that we do with our systems, we don't need anyone's approval, and we don't all have to do the same things.

            • #1540206

              With”fastboot” on, the PC remains in the Windows 10 environment, and is not completely powered down. It is in a low power state, not “off”. With a PC in BIOS/MBR the BCD store is on the boot drive, and resuming from hibernation simply calls the “resume object” …
              (blue emphasis is mine)

              So if I remove the power overnight (pull the battery or the plug of a desktop), it won’t resume any more, because the low power state is then fully powered down too. That’s easy enough to test.

              Not that I will actually test do the test, as I don’t use “fast start” nor hibernation anyway, because I don’t like a hibernation file, a pagefile and temp files on my SSD (I configured Windows to write pagefile and temp files to the HDD, to limit the activity on the SSD).

              Well, thanks guys. It’s been an interesting thought experiment.

    • #1540112

      Where is the BCD file located in the registry?

      BIOS-based operating systems. The BCD registry file is located in the BootBcd directory of the active partition.

      EFI–based operating systems. The BCD registry file is located on the EFI system partition.

      Maybe you some how have both of these ? Not that solves the mystery but it would be another clue.

      :cheers:

      🍻

      Just because you don't know where you are going doesn't mean any road will get you there.
    • #1540115

      Do you have an EFI partition by chance?
      42797-Untitled

      :cheers:

      🍻

      Just because you don't know where you are going doesn't mean any road will get you there.
    • #1540452

      I didn’t know this: “When using fast startup, the system appears to the user as though a full shutdown (S5) has occurred, even though the system has actually gone through S4.”

    • #1540575

      🍻

      Just because you don't know where you are going doesn't mean any road will get you there.
      • #1540580

        A picture IS worth 1k words.
        42814-2768.Relative-time-needed-for-different-phases-of-startup_thumb_0ABE24BF

        :cheers:

        http://blogs.msdn.com/b/b8/archive/2011/09/08/delivering-fast-boot-times-in-windows-8.aspx

        Right. And in a dual boot environment where (other than for updates requiring reboot) the only time I reboot is to get to the other OS, the Windows 8/10 bootmgr partially boots, then totally reboots. I’d rather just totally reboot to get to the other side, and not waste the time for that unnecessary partial boot into the wrong OS. It’s like putting both parts of your bar chart together, end-to-end:p Picture that:rolleyes:

        Always create a fresh drive image before making system changes/Windows updates; you may need to start over!
        We were all once "Average Users". We all have our own reasons for doing the things that we do with our systems, we don't need anyone's approval, and we don't all have to do the same things.

        • #1540595

          I’d rather just totally reboot to get to the other side, and not waste the time for that unnecessary partial boot into the wrong OS. It’s like putting both parts of your bar chart together, end-to-end:p Picture that:rolleyes:

          bbearen,

          If you use EasyBCD & iReboot a simple click on the taskbar icon to select the desired OS and it’s done.

          42817-ireboot
          HTH :cheers:

          May the Forces of good computing be with you!

          RG

          PowerShell & VBA Rule!
          Computer Specs

          • #1540614

            bbearen,

            If you use EasyBCD & iReboot a simple click on the taskbar icon to select the desired OS and it’s done.

            42817-ireboot
            HTH :cheers:

            But you know how much I like my piddlin’ with Windows, RG! I used DISKPART to give the EFI partition a drive letter, then went in using the Command Prompt and renamed the Windows 8 bootmgr, copied in the Windows 7 bootmgr, then DISKPART again to remove the drive letter.

            And working with BCDEDIT gives me a better understanding of how the whole boot process works. I have EasyBCD installed but haven’t used it in quite some time. There’s a certain satisfaction and glint of understanding that comes with doing things my own way that installing a utility can’t quite match;)

            Always create a fresh drive image before making system changes/Windows updates; you may need to start over!
            We were all once "Average Users". We all have our own reasons for doing the things that we do with our systems, we don't need anyone's approval, and we don't all have to do the same things.

            • #1540641

              …There’s a certain satisfaction and glint of understanding that comes with doing things my own way that installing a utility can’t quite match…

              You might find benefit from having a closer look at TerabyteUnlimeted’s BootItBM Boot Manager rather than your present somewhat limited ‘Image for Windows’ & BCDEdit solution.

              BootItBM includes ‘Image For DOS’ which I have used hundreds of times to create backup images of Windows partitions before making major changes to the customers’ OS partition. ‘Image For DOS’ lets me image a partition outside Windows, so it usually doesn’t matter if the customers’ OS partition won’t boot. At very least I can extract the customers’ files from the image.

            • #1540654

              You might find benefit from having a closer look at TerabyteUnlimeted’s BootItBM Boot Manager rather than your present somewhat limited ‘Image for Windows’ & BCDEdit solution.

              I started with BING (BootIt Next Generation) in the ’90’s, and upgraded to BootItBM when it became available. That was my boot manager until UEFI. BootItBM cannot be installed on a UEFI system; it requires an EMBR partition for installation, and EMBR is not compatible with UEFI. It can be used for partition management, etc. (it understands GPT) but it has to be booted from USB or CD for such purposes. I use BootItBM for all my partitioning needs.

              Image For Windows also includes Image For DOS as well as Image For Linux and Image For UEFI. One of TereByte’s freebies for registered users is TBWinRE, a recovery environment that can be built which combines WinRE.wim along with an installation of Image For Windows. It will boot in either UEFI/GPT or BIOS/MBR, has all the tools available in the Windows Recovery Environment as well as Image For Windows.

              IFW and IFD both use the same imaging system, so each can read/restore image files from the other. My TBWinRE USB thumb drive is the only tool I carry when I do my “Computer guy” help for my friends and relatives. I can boot any PC with it as long as the motherboard isn’t fried. There’s room on the thumb drive for a folder of my favorite tools/utilities, as well.

              I’m not as limited as one might think.

              Always create a fresh drive image before making system changes/Windows updates; you may need to start over!
              We were all once "Average Users". We all have our own reasons for doing the things that we do with our systems, we don't need anyone's approval, and we don't all have to do the same things.

            • #1540770

              . There’s room on the thumb drive for a folder of my favorite tools/utilities, as well.

              Do these run in the BBM boot environment?
              I have never got the simplest stuff to run in Acronis PE boot:(
              :cheers:

              🍻

              Just because you don't know where you are going doesn't mean any road will get you there.
            • #1540789

              Do these run in the BBM boot environment?
              I have never got the simplest stuff to run in Acronis PE boot:(
              :cheers:

              That thumb drive is not for BootIt Bare Metal, it’s for TBWinRE, a Windows Recovery Environment that is modified using the free tool download available from TeraByte Unlimited. It is the complete WinRE.wim with Image For Windows added to the .wim file. I have a dedicated small capacity thumb drive for BootItBM that I just use for partitioning, BCD editing and such.

              The TBWinRE thumb drive has all the Windows tools that are available in the Windows Recovery Environment (what you get when you select “Repair” when booted to a Windows installation DVD). A couple of my utilities will run under a Command Prompt, which is one of several options in WinRE. My troubleshooting tools/utilities are in a folder on the thumb drive, so once I get the troublesome PC to boot into Windows, those tools that run in Windows are right at my fingertips.

              Always create a fresh drive image before making system changes/Windows updates; you may need to start over!
              We were all once "Average Users". We all have our own reasons for doing the things that we do with our systems, we don't need anyone's approval, and we don't all have to do the same things.

        • #1540767

          Right. And in a dual boot environment where (other than for updates requiring reboot) the only time I reboot is to get to the other OS, the Windows 8/10 bootmgr partially boots, then totally reboots. I’d rather just totally reboot to get to the other side, and not waste the time for that unnecessary partial boot into the wrong OS. It’s like putting both parts of your bar chart together, end-to-end:p Picture that:rolleyes:

          πŸ™ I would rather not. This is one of the reasons my ‘dual boots’ these days go from the Bios/Uefi boot menu. There is an occasional problem where W10 wants to do a checkdisk when started after a previous W…..

          🍻

          Just because you don't know where you are going doesn't mean any road will get you there.
          • #1540788

            πŸ™ I would rather not. This is one of the reasons my ‘dual boots’ these days go from the Bios/Uefi boot menu. There is an occasional problem where W10 wants to do a checkdisk when started after a previous W…..

            I’ve seen some references that point toward System Restore in the case of a Windows/Windows dual boot. With System Restore enabled on both, each OS has an opportunity to write to the System Volume Information folders (which contain restore point information as well as other system information) and this can cause issues.

            I disable System Restore on all my systems, and I’ve never had an issue with checkdsk wanting to run on a reboot (except when I actually had a failing disk with Windows 8.1). Not saying that it is definitive, but that’s been my experience.

            I’ve seen too many sad tales about System Restore failing to Restore the System; I don’t care for the idea of System Restore from the git-go; dedicated to drive images for that sort of stuff. Yes, I know that lots of folks use it and lots of folks have had no problems with it, but I’m almost certain that if I disable it and don’t use it, it can’t leave me in the lurch.

            Always create a fresh drive image before making system changes/Windows updates; you may need to start over!
            We were all once "Average Users". We all have our own reasons for doing the things that we do with our systems, we don't need anyone's approval, and we don't all have to do the same things.

            • #1540817

              I’ve seen some references that point toward System Restore in the case of a Windows/Windows dual boot. With System Restore enabled on both, each OS has an opportunity to write to the System Volume Information folders (which contain restore point information as well as other system information) and this can cause issues.

              I am guessing, since system restore was disabled on W10 I went ahead and enabled it. BAD fingers BAD. πŸ˜‰
              :cheers:

              🍻

              Just because you don't know where you are going doesn't mean any road will get you there.
    • #1540773

      http://windowssecrets.com/forums/showthread//173000-upgrade-to-Win10-in-dual-boot-environment?p=1033898&viewfull=1#post1033898

      I am still confused by the behavior described here: both W7 and W10 bootmanagers being available depending on whether fast start is active on W10!

      Oh I guess like the Iris Dement song goes I’ll Let The Mystery Be!

      🍻

      Just because you don't know where you are going doesn't mean any road will get you there.
      • #1540786

        With fast start ON the monitor shows at power up:
        1. the computer dealer’s splash screen (no owlish head), + the message Resuming from hibernation, all white on black, and NO setup or boot order options,
        2. the Win10 logo, light blue on black, and the ring of tail chasing marbles, white on black,
        3. the Win10/Win7 boot options, light blue graphics on darker blue, like in your bootmgr 8 clip, and further on the same behavior and looks, i.e. it reboots on Win7 choice.

        With fast start OFF it shows:
        1. the computer dealer’s splash screen + the setup and boot order options, white on black
        2. the Windows boot manager menu with 2 boot options, white letters on a black screen, no marble circles appeared yet,
        3. from there on it proceeds directly to the chosen option (no reboots either way), marbles for Win10, animated logo for Win7.

        I am still confused by the behavior described here: both W7 and W10 bootmanagers being available depending on whether fast start is active on W10![/QUOTE]
        ”Resuming from hibernation” is not a boot or a reboot. The system is not completely powered off, it is in the S4 power level. He said his PC is setup BIOS/MBR, not UEFI/GPT. That means that the bootmgr in use is in the root of the system drive, not in an EFI partition. That also allows for two bootmgr’s to be available on his PC, because the Windows 10 bootmgr is in the root of the Windows 10 drive, and the Windows 7 bootmgr is in the root of the Windows 7 drive. These drives can be either physical hard disks or logical drives (partitions on a single hard disk).

        The drive that is flagged as the boot drive determines the bootmgr that is used. If Windows 7 is preexisting on the PC when Windows 10 is installed in a BIOS/MBR environment to a separate drive/partition, the BCD store in the boot drive is modified.

        In october I repartitioned my system SSD, which restored my PC to its brandnew (Febr 2015) and virginal condition, or almost anyway. Then:

        1. I clean installed Win7/32 to the *4th* partition.

        2. The boot manager showed 1 entry: Win7.

        3. I clean installed Win10/64 to the *1st* partition and as default OS.

        4. The boot manager still showed only 1 entry: but now it was Win10.

        5. Win10 running, I coaxed EasyBCD to put the Win7 entry back in the boot manager as secondary OS.

        6. After shutting down from Win10 with fast start OFF, the PC behaves like in your Windows 7 bootmgr video.

        7. After shutting down from Win10 with fast start ON, the PC behaves like in your Windows 8 bootmgr video.

        (EasyBCD doesn’t do anything to the bootmgr, it only edits the BCD store. Bootmgr displays the boot menu, but the boot menu resides in the BCD store.)

        The above described behavior is the difference between “Resuming from hibernation” in a Fast Start environment and an actual cold boot. The resuming from hibernation behavior in Fast Start is a hybrid boot behavior, and in a dual boot setup (reading the BCD store and “seeing” a boot option) the hybrid boot behavior calls the bootmgr to offer the boot options.

        In this case, it calls the bootmgr that is in the root of the hybrid boot drive (the OS that is already loaded in the hibernation file) which is the Windows 10 drive, and thus the Windows 10 bootmgr is what is called to display the boot menu.

        With Fast Start turned off, the normal boot process looks to the drive flagged as the boot drive for the bootmgr, which in this case is the Windows 7 drive and the Windows 7 bootmgr.

        Always create a fresh drive image before making system changes/Windows updates; you may need to start over!
        We were all once "Average Users". We all have our own reasons for doing the things that we do with our systems, we don't need anyone's approval, and we don't all have to do the same things.

        • #1540840

          In this case, it calls[/B] the bootmgr that is in the root of the hybrid boot drive (the OS that is already loaded in the hibernation file) which is the Windows 10 drive, and thus the Windows 10 bootmgr is what is called to display the boot menu.

          With Fast Start turned off, the normal boot process looks to the drive flagged as the boot drive for the bootmgr, which in this case is the Windows 7 drive and the Windows 7 bootmgr.[/SIZE]

          Thanks BB, I got most of that but WHAT in an MBR system is it that does the calling? Does not the MBR point to one spot and lets the next step be handed off there?

          🍻

          Just because you don't know where you are going doesn't mean any road will get you there.
          • #1540851

            Thanks BB, I got most of that but WHAT in an MBR system is it that does the calling? Does not the MBR point to one spot and lets the next step be handed off there?

            It [/B]is the BIOS. This link gives a pretty detailed description of the Windows 7 boot process. Note that the last thing that the BIOS does is read the MBR after it detects a valid system disk. After reading the MBR, the BIOS starts Bootmgr.exe which takes over the boot process.

            Bootmgr reads the BCD store and follows instructions from there. On a dual boot system, the BCD store consists of at least 3 major headers; Windows Boot Manager, Windows Boot Loader, and another Windows Boot Loader. The last entry in the Windows Boot Manager header is (without the quotes) “displaybootmenu Yes”. When the user selects the desired menu item, bootmgr follows the instructions for that Windows Boot Loader, one of which is where to look for the Windows loader. The drive is listed, and the default path is windowssystem32winload.exe (for a UEFI system it’s windowssystem32winload.efi)

            That’s on a cold boot, or a normal reboot. Waking from hibernation follows a different route. The BIOS detects that the system power state is S4, which means that the OS is in hibernation and a slightly different journey is taken to load hiberfil.sys into RAM. Bootmgr reads the “resumeobject” ID. There’s no need to “load” Windows because once hiberfil.sys is loaded into RAM, so is Windows. The part of RAM that’s always unavailable to the user is the Windows kernel and other files and all the necessary drivers. This link relates an issue I had with my laptop, the sleep state, and the hibernation state.

            Fast start is a hybrid boot, where the OS is in hibernation but for all practical purposes appears to the user as powered off. Part of that hybrid boot process is to call the bootmgr from the system drive root, and since Windows is already loaded, bootmgr calls the “resumeobject”. In a single OS system, a logon screen comes up. In a dual boot, a boot menu comes up. If the other OS is selected, the system has to reboot in order to unload the Windows that is in RAM and call the other Windows Boot Loader.

            In a UEFI system, the BIOS knows that the bootmgr is in the EFI partition. The other parts of the boot process in UEFI are pretty much the same as in BIOS.[/SIZE]

            Always create a fresh drive image before making system changes/Windows updates; you may need to start over!
            We were all once "Average Users". We all have our own reasons for doing the things that we do with our systems, we don't need anyone's approval, and we don't all have to do the same things.

    • #1541144

      I am gonna have to read and think. Thanks for your answer.

      BTW good music on that you tube vid of the different boot managers!!

      :cheers::cheers:

      🍻

      Just because you don't know where you are going doesn't mean any road will get you there.
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    Reply To: upgrade to Win10 in dual boot environment

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