1. Originally only Windows 7 was installed on a partition. The first partition was a 100MB recovery partition while the Windows OS and data files was on the second partition.
  2. Then I installed Ubuntu on a third partition. Grub took over the booting process and I had to manually reconfigure grub to get Windows 7 bootable again.
  3. Eventually I decided to remove Ubuntu and try out Windows 10 so that the PC can dual boot between Windows 7 and Windows 10.
  4. The Ubuntu partition is reformatted and replaced Windows 10, Grub is replaced with whatever Windows 10 uses to boot and Windows 7 is no longer an available option to boot.
  5. Removed the first "recovery partition" since it couldn't recover my installation anyways.

Current Setup

So currently my partition layout looks like this:

  • First partition: Unallocated space (where recovery partition used to be)
  • Second partition: Windows 7 (System, Active, Primary)
  • Third partition: Windows 10 (Boot, Page File, Crash Dump, Primary)
  • Fourth partition: Extended partition with free space (currently not used)

My partition table is MBR. I had to turn on "legacy boot" option in my BIOS to allow Windows 10 to install.

I haven't touched the second partition with Windows 7 so all the system files should still be intact. Windows 10 was a clean installation on a separate partition.

Both my Windows 7 and Windows 10 installation disks does not recognise my Windows 7 installation (possibly because of Grub?) so the "Auto repair" option is not an option for me.


How can I MANUALLY repair the "boot-loader" so that I can boot both Windows 7 and 10?


Use bootrec /rebuildBCD in a recovery environment to find your other windows OSes and fix the bootloader. Make sure it finds both your Windows 7 and 10 installs.


  • bootrec /RebuildBcd did the trick for me. Thank you very much!!! – Jasper Citi May 22 '16 at 18:26
  • @Koning No problem! Glad I could help. – TheKB May 22 '16 at 19:17

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