How to get Windows booting after uninstalling Ubuntu?

Solution 1:

The answer depends on whether the system was booting with BIOS or with EFI. vfbsilva's answer might work with BIOS-based computers. (It definitely works with old versions of Windows, but I'm not sure if the same procedure works with Windows 8.)

The vast majority of new computers that ship with Windows 8 are EFI-based. On such a computer, you need to restore the Windows boot loader to be the primary one and/or delete GRUB from the EFI System Partition (ESP). You can set the Windows boot loader to be the primary one in various ways, but unfortunately, they all take a lot of explaining and/or are tricky to do. Deleting GRUB from the ESP is relatively easy to explain, so I'll do that:

1. Boot a Linux live CD.
2. Identify your ESP by typing sudo parted /dev/sda print and locating the partition with the "boot flag" set.
3. Mount the ESP by typing sudo mount /dev/sda1 /mnt (substituting the correct device identifier for /dev/sda).
4. Type sudo rm -r /mnt/EFI/ubuntu to remove Ubuntu's version of GRUB. If you've manually installed GRUB somewhere else, remove it instead of or in addition to Ubuntu's GRUB.
5. Reboot.

When you reboot with GRUB absent, the computer will bypass that no-longer-functional entry and use the next one in its list, which should be the Windows boot loader.

A caveat: If you've used Boot Repair, you may need to re-run it and use its advanced options to undo its renaming operations. If you fail to do this, you'll end up still running your non-functional GRUB.