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  • Remove Windows 10 from a 7/10 dual-boot

    Home Forums AskWoody support Windows Windows 7 Questions: Windows 7 Remove Windows 10 from a 7/10 dual-boot

    This topic contains 5 replies, has 2 voices, and was last updated by  Paul T 4 weeks, 1 day ago.

    • Author
    • #2085932 Reply


      Hello, I need help with an issue extricating a windows 7/10 dual boot system. Windows 7 was the primary and is still the mainly used OS, and Windows 10 was added on it’s own SSD a couple years ago. My goal is to remove the windows 10 SSD to nuke an re-use in a new system, and keep windows 7. I have modified msconfig, and the current system boots directly into W7 as desired.

      The problem is, when I unplug one of the OS drives, neither will boot on its own.

      I get the feeling I made an amateur mistake and I’m going to face-palm when someone tells me what I missed…

    • #2086141 Reply

      Paul T
      AskWoody MVP

      Legacy boot is very fussy about disk setup and you have probably managed to mix boot information across both drives.

      1. Image backup.
      2. Create / obtain a W7 boot / rescue CD/USB.
      3. Remove the W10 disk.
      4. Boot from the W7 CD.
      5. Recover the boot system – can’t remember the exact sequence.

      cheers, Paul

    • #2086363 Reply


      Must be a matching edition install disc? Do I use bootrec /fixmbr, bootrec /fixboot or rebuild bcd? Or all three?

    • #2086603 Reply

      Paul T
      AskWoody MVP

      Don’t think the edition matters.
      See this post for a nice description of recovering the boot.

      cheers, Paul

    • #2110792 Reply


      Fixed it with a cable swap. Apparently BIOS doesn’t align AHCI P0 with Sata port 1, moving the 7 drive from the cable attached to P0 to the cable marked as “SATA” (physical port Sata2-L) in BIOS BBS priority. As the 7 drive was the original system drive, once it was on this port, it is receiving boot priority and works as desired, with or without the W10 disk attached. In the process I ended up using another drive for my new system, leaving me capable of keeping 10 on the current system.

      The problem now is the W10 disk will not boot, either by itself attached to any port, or with the 7 drive attached. Ran fixmbr succsessfully, but fixboot came up element not found. Found there is no system reserved partition on the 10 drive, presumably since it was subordinate to Windows 7. Do I have to create a system reserve partition?

    • #2111041 Reply

      Paul T
      AskWoody MVP

      10 uses a different boot mechanism to 7 (usually).
      You should have 2 partitions on the W10 disk, “EFI System” and the C drive. The boot files are on the system partition and as long as your BIOS is in UEFI mode it should boot.

      Connect the disk, fire up W7 and run “diskmgmt.msc”. Post a screenshot of the partitions on the W10 disk.

      cheers, Paul

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