When I removed a failed to load Kubuntu partition on my dual boot laptop, I did something stupid: I rebooted the computer.
Of course I ended up with Grub “Error 22”.
Fortunately I had a recovery DVD with system files and after booting from this DVD and getting into the command line, I found file bootrec.exe.
Executing it as:
restored the MBR and I was able to boot into Vista.