I have a Lenovo e570 laptop. I can't find Windows in the GRUB boot menu after installing Ubuntu, and I am interested in booting Windows 10 again.

I had the usual problem of not seeing Windows 10 in the boot option after installing Ubuntu. I tried sudo update-grub and boot repair (with different options), but it didn't work. Here's the Boot Repair Boot Info Script.

This is a screenshot from the GParted screen showing unexpectedly that a boot flag is on the FREE_DOS partition. Is there a problem with the flags?

enter image description here

I also tried using a Windows USB stick to fix the startup issues, but it didn't work.

The partition with Windows 10 exists and is mountable with everything in it.

I ran Boot Repair again and this was the result. Also the Repair Windows boot files option is still grayed out.

Is there any specific option for Boot Repair when it is the efi/legacy problem? I tried the separate efi partition option.

Also, what should the BIOS options be for UEFI/Legacy booting?

  • I tried the suggested answers and they didn't work for me, now I have an entry in the grub menu for "Windows (UEFI)" and it leads to an error message from windows that I need a repair disk. I tried the windows repair disk again but it didn't work. – zixmarkiz Feb 10 '18 at 18:13
  • this is a screenshot from the gparted screen, is there a problem with the flags? ibb.co/gUMwY7 – zixmarkiz Feb 10 '18 at 18:19
  • I reran boot-repair again and this was the result: paste.ubuntu.com/=2PnpzFYM8T Also the Repair Windows boot files option is still grayed out. – zixmarkiz Feb 10 '18 at 18:32

You have mixed UEFI & BIOS. They are not compatible, but just different boot options in UEFI. And Windows in BIOS boot mode must use MBR partitioning. And normally UEFI installs use gpt partitioning.

It looks like you have a BIOS/CSM/Legacy install of Windows on MBR partitioned drive. But installed Ubuntu in UEFI mode, but still on MBR drive which is unusual as UEFI normally is gpt partitioned. But Windows in BIOS mode must use MBR.

Boot Ubuntu installer in BIOS mode, install Boot-Repair and in Boot-Repair's advanced options run the full uninstall/reinstall of grub. That should uninstall grub-efi-amd64 (UEFI) and install grub-pc (BIOS). You want to convert Ubuntu to BIOS boot.

Since Windows is BIOS, you need to always boot in BIOS mode. But since hardware is newer UEFI with newest SSD, you may want to consider reinstalling Windows in UEFI mode.

How you boot install media, UEFI or BIOS is then how it installs for both Ubuntu & Windows.

Separately your p2 partition is full. NTFS really likes 30% free to work well. At 20% free it slows and at 10% free you have no working room to run a defrag.

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