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  • Change Legacy Boot to UEFI

    This topic contains 6 replies, has 4 voices, and was last updated by  MisterKevin 11 months, 3 weeks ago.

    • Author
    • #214416 Reply


      Hello, I would like to set my Windows 10 laptop to boot in UEFI mode, but for some reason Windows will not start when I change it from Legacy mode. Here’s what happened:

      A little while ago, everything was running normally (booting in UEFI). Then the only hard drive failed. I replaced it myself, and reinstalled Windows 10 on the new (empty) hard drive. I had to go into the BIOS settings and change the boot mode to Legacy, so that it could use the boot media on the USB drive. I successfully ran the installer and set up Windows 10; however, I seem to be stuck booting in Legacy mode. If I try to boot in UEFI, the screen will display “checking media” for a few seconds, then shut off, only to start again, repeat the message, and die.

      If anyone knows of a way to change this, please let me know! I plan on just running my computer in Legacy boot mode, but I would prefer to change it, if possible.

    • #214436 Reply

      AskWoody Lounger

      Win10 x86 (32bit) or Win10 x64 (64bit amd64)?? To run Win’s 7 to 10 they normally have to be installed with UEFI on a GPT Disk with x64 on a Machine that is X64 capable. Not really heard of or used an MBR (Legacy scenario) for UEFI, strange. Although you can Boot Win10 in legacy mode. in times of need. Its not something I do or recommend as a rule. Errm is it possible you installed Win10 x86 or x64 in MBR Disk format?? Normally I use RUFUS with an x64 install media set to UEFI / GPT. Something in a similar vein in here if memory serves me right:
      Hate to suggest this but back up your data and possible a clean install, unless you want to try the repair process “BOOTREC” commands.
      You can convert to GPT using these CMD’s by hitting SHIFT + F10 at the first setup screen when you create and install USB per Rufus with a Win10 x64 image

      Hopefully some one else can suggest something I am missing here I wouldn’t like to send you down the reinstall path needlessly, Normally what fix’s it for me but generally manifest’s its self after a clean install, so I just redo without investing too much time in to the OS extremely unusual for it to happen after a while. Have you checked the health of your Disk??? Hope this helps a little.
      PS the “Format Options” with the illus. above refers to the demeanour of the USB stick not your actual Disk that will get the OS. Win 10 install media can be found here: Dont use the Microsoft recommendations create an .ISO x64 for use on another Machine. ie don’t allow it to attempt upgrade/date you in place its fairly self explanatory and you get a back up .iso for future emergencies.

      3 users thanked author for this post.
      • #214592 Reply

        AskWoody Lounger

        It is a Win10 x64 device, and I installed the 64-bit version. The hard drive is brand new, and I used this USB drive to install Windows 10, since I don’t have another PC to create the Windows 10 boot media. I had to set my laptop to boot in legacy for the purpose of booting from the USB drive. I’ve attached a copy of the instructions. I plan on trying @paul-t ‘s suggestion, since I am not sure how I could reinstall Windows 10 in UEFI. Would using the Windows 10 iso file do that, and would I have to boot Legacy to use it? I already used the Reset option within Windows, but that didn’t make a difference.

        • #214628 Reply

          AskWoody Lounger

          @misterkevin Win10 is as easy as I described no need to turn off Secure Boot (enabled) as all the Boot Drivers are “Signed” as for legacy mode (set disabled) x64 can go straight in no problem UEFI, no changes at all whatsoever. If you really want to ensure its GPT from the get go (although there shouldn’t be a need) when you get to the first Screen where you enter language settings etc:
          Pres SHIFT F10
          brings you to an x:\ (prompt then type)
          LIST DISK
          SEL DISK 0 (if that’s your C:\drive)
          CLEAN (be sure that’s what you want there’s no going back)
          CONVERT GPT
          and that’s it continue as normal following the instructions
          Win 10 can be installed with UEFI enabled and Secure Boot enabled no worries, but by all means give @paul-t ‘s method a go first but make sure you have backed up whichever way you choose Hope it works out for you 🙂
          PS as for Booting from USB while your in the BIOS turn off Legacy, Enable Secure Boot, selecting boot from USB shouldn’t affect those settings and it should boot from a USB prepared as above. Match carefully the wording as displayed, there’s lots of variants with RUFUS its a useful tool however

          1 user thanked author for this post.
    • #214499 Reply

      Paul T
      AskWoody MVP

      It’s easy according to Intel (?)

      I would make an image backup before attempting this.

      cheers, Paul

      4 users thanked author for this post.
      • #214501 Reply

        AskWoody Lounger

        @paul-t hey nice find there, sort of heard about it last year but never got round or needed to use it. It would have been nice when a few years ago I was trying to get a Win7 installation to work UEFI on a couple of Laptops and I had tried a few methods, needless to say, that were destructive on the HDD contents. Should fit the bill perfectly I would imagine if that’s @misterkevin ‘s problem. Its always easier when you have a Machine in front of you to diagnose and fix rather than suggest blindly. Hopefully that works far better than some of the “in Depth” methods I suggested 🙂

    • #214937 Reply

      AskWoody Lounger

      Hey, I followed the instructions in @paul-t ‘s link, and successfully changed from legacy boot mode to UEFI in about 5 minutes! Thanks for all the help!

      1 user thanked author for this post.

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