Formatted Ubuntu partition & now grub says "error: no such partition" - can't enter windows

Question

I had installed Ubuntu (current version: 11.xx) alongside Windows Vista. Now I formatted the Ubuntu partition & merged it with another partition (without thinking, obviously).

Now, when I restart the computer, GRUB probably tries to find the old partition (which does no longer exist) and says:

error: no such partition.
grub rescue>

Now I dont know what to do (I'm a total beginner). I tried to re-install Ubuntu on the newly formatted partition but this won't work, because after removing the install-usb (which I am said to do during installation) I find the above error-message again.

I guess I need some way to reconfigure grub OR to reinstall grub/ubuntu (on the newly formatted partition) OR to reinstall the windows boot manager (without reinstall. Windows), but I have no idea how to do either of these things.

Solution

GRUB, as installed by Ubuntu, won't work without access to the Ubuntu partition. The easiest solution is to reinstall windows bootloader. You should start your computer with the windows installation disk, select the repair option, select the command prompt repair. Type:

Bootrec.exe

You can install Ubuntu afterwards.

Comments

[Scott Severance]

Are you sure that GRUB won't work without Ubuntu? I've never tried it, but since it operates at the MBR level, it should theoretically be OS-independent.

[Javier Rivera]

You're right, it's OS independent. But, when installed from Ubuntu, it's files are stored in the Ubuntu partition. If you delete it, GRUB will break.