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I have a dual-boot computer and used to be able to boot both to Windows 7 and Ubuntu 18.04.

Since recently the grub selection menu does not show windows anymore. Booting to Ubuntu still works fine.

As I was not able to fix the problem so far, I need your help.

Here is the output of boot-repair: http://paste.ubuntu.com/p/vVbDwv3948/

Please let me know if you need any additional information or log files.

Thank you!

Best, Christian

Christian Zimpelmann
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1 Answers1

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This is really a Windows fix that is required.

Grub2's os-prober looks for Windows boot files. Vista/7/8/10 BIOS (with 7, 8 or 10 the first two files are usually in a separate 100MB boot partition) /bootmgr /Boot/BCD /Windows/System32/winload.exe

Windows 7 in BIOS boot mode typically has a separate Boot partition, your sda1 and Windows uses boot flag to know which partition has those boot files.

Your sda1 is not showing any boot files, you need to restore bootmgr & BCD using a Windows repair disk. You cannot fix it from Linux.

Some alternative fixes here. but best to use Windows repair console from your Windows repair flash drive.

How to remove Ubuntu and put Windows back on?

oldfred
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  • Thank you very much for your answer!

    Aren't there windows boot files on sda2?

     – Christian Zimpelmann Nov 22 '18 at 16:30
  • You are showing winload.exe. There maybe a backup of bootmgr somewhere, but generally you have to recreate BCD. Some third party tools will also work to create new BCD. Always best to back the Windows boot partition up also. Boot-Repair typically copies those boot files to main (c: ) drive so you have copies, but then os-prober sees both sets of boot files and offers two Windows boot options which boot normally work. – oldfred Nov 22 '18 at 21:16