Lost my Windows boot option while dual booting with Ubuntu

Question

I had a problem with my dual boot laptop. I've had dual booted Windows and Linux for like 1 year, but I wanted to update my Ubuntu or to reinstall it. So I've done that but forgot to check the radio button that says Install Ubuntu alongside with Windows. So that happened... I've lost my boot entry to Windows. Is there any way that I could recover it.

And yes, I've checked the GParted and it says that the partition is there, as well as all files in it.

Edit: I am not sure, but as I can remember there was no UEFI Boot when I was selecting boot location. Is there a way that I can check that? Because it was long ago, I finally found time to fix it, because it was not bothering me. The button I selected said only Install Ubuntu. I forgot to say that the GRUB isn't showing on boot.

Thank you!

Take a screenshot of Gparted. Upload the screenshot in imgur.com and edit the question and add the link to the screenshot in your question above. If you forgot the radio button to install alongside Windows, which button did you select? Did you install in UEFI or Legacy BIOS (CSM) mode? Is Windows installed in UEFI mode or not? Please add all these new information in your question. — user68186, Sep 05 '19 at 21:07
Possible duplicate of Add Windows 10 to GRUB OS list and Unable to boot into Windows after installing Ubuntu, how to fix? — karel, Sep 06 '19 at 12:38
It looks like Windows was installed in BIOS or Legacy mode and Ubuntu in UEFI mode. I may be wrong. — user68186, Sep 06 '19 at 13:06
I am sure that windows is in BIOS mode, but not sure about Ubuntu — M.Simel, Sep 06 '19 at 14:02
The /dev/sda6 FAT21 partition is an EFI System Partition (ESP). See the boot, esp flag. Since this is a logical partition inside the /dev/sda3 extended partition, I think it was created during Ubuntu installation. This makes me think that Ubuntu was installed in UEFI mode. See this answer to differentiate between UEFI and BIOS mode Live-USB boots. You may be able to use grub-repair as explained in the duplicate linked answers. — user68186, Sep 06 '19 at 16:51
Possible duplicate of Unable to boot into Windows after installing Ubuntu, how to fix? — karel, Nov 05 '19 at 18:50

score 0 · Accepted Answer · answered Nov 05 '19 at 18:47

I have noticed that my boot was in EFI boot, but the windows was installed on legacy boot. So the answer was to disable EFI boot and do it as a legacy boot option. Then it should boot into the Ubuntu, with the grub loader but with no option about windows. Then, you just have to use boot repair. That's it!

Lost my Windows boot option while dual booting with Ubuntu

1 Answers1