Recently I've bought second HDD (B) for Linux (My configuration was: One dual-boot HDD (A) with Windows 7 + Ubuntu 16.04 on separate partitions). I've deleted Linux partition from my old HDD and extended Widows partition to fully use drive A. After rebooting I was greeted by some error like "no boot device". Without worrying much about it I've decided to install Ubuntu 18.10 on the second drive following guide from this thread. After installing like in guide and booting into Ubuntu (grub didn't show even for 1 second) I've installed grub-customizer, where I found out that grub show time was set for 0 seconds, so I've changed it to 5s. But: Windows weren't among boot options (even after sudo update-grub which used to help in the past). After trying to reboot PC not only was there no option to choose Windows in grub - the grub didn't show at all! The screen turned purple for few seconds, but then Ubuntu logo appeared and the system booted. I've tried default boot-repair repair, but it didn't help. Here is the BootInfo pastebin.

  1. How do I get grub to show?
  2. How do I get Windows to show inside grub?
  3. Is there any other way to boot into Windows If I need to?

Edit: I've managed to make grub to show by pressing ESC key during purple screen. I'm not sure why doesn't grub show by default, because I've check "show menu" option in grub-customizer and commented GRUB_HIDDEN_TIMEOUT=0 inside /etc/default/grub too. Still no option to boot Windows.

Edit2: I've managed to repair Windows 7 boot by changing BIOS settings back to legacy+UEFI and using Windows 7 Recovery CD to fix "bootmgr is missing". I still cannot see Windows 7 in grub, but I can boot both systems by changing drive boot order. How can I add Windows 7 to the grub so that I won't have to do it every time I start computer?

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    Possible duplicate of Add Windows 10 to GRUB OS list
    – karel
    Mar 6, 2019 at 13:26
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    @karel, that question is all too weird by itself, but it does seem that in that case that it looked like that person, like OP here, had a situation where Windows was a BIOS installation and Linux was a UEFI one. So, with a bit of timidity since at least this question is much more specific and well-asked, I agree that this is also a possible duplicate of Add Windows 10 to GRUB OS list Mar 6, 2019 at 14:08
  • @karel, wait, I guess I didn't do this right, I'm supposed to flag it and a comment will automatically appear. I'll get this right. Mar 6, 2019 at 14:10
  • Huh, I flagged it, and it upvoted you, @karel. Well I did it then. Mar 6, 2019 at 14:11

1 Answer 1


From the information provided, I think Windows 7 is installed in BIOS mode while Ubuntu was installed in UEFI.

In my opinion its simpler to re-install Ubuntu in BIOS mode.

Edit- As pointed out by @oldfred, you can install Grub in BIOS mode while in Boot repair rather than complete reinstall. Check in the comment below.

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    Yeah, I feel, that if this person's firmware is UEFI and he followed to the letter of askubuntu.com/questions/726972/…, no wonder this mess happened. :P Mar 6, 2019 at 14:01
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    Total reinstall of Ubuntu not required. You just need to add a tiny 1 or 2MB unformatted partition with bios_grub flag. (See line 927 in report). And then reinstall the BIOS version of grub. Often easier with Boot-Repair, but boot Ubuntu live installer in BIOS mode. Boot mode is selected in UEFI when booting live installer. This shows first screen when booting to know if UEFI or BIOS boot. Shows installer with screen shots. Both BIOS purple accessibility screen & UEFI black grub menu screen help.ubuntu.com/community/UEFI or re-install Windows in UEFI mode.
    – oldfred
    Mar 6, 2019 at 14:34
  • @RoundDuckMan, yeah, but I would blame the tutorial more rather than the OP.
    – abchk1234
    Mar 7, 2019 at 6:20

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