If you’re like me — a fanatic Linux tester using Windows part time — you’ve probably experienced a few installation failures. When that happens, sometimes the Linux installation breaks the grub boot loader, leaving you with a computer that won’t do anything besides displaying a discouraging black grub console. Well, here’s how to actually boot your Windows installation manually from that grub console. If the console isn’t already there when you start the computer, simply hit ‘c’ and then type the following:

rootnoverify (hd0,0)
chainloader +1
boot

That will boot you into Windows again, so you can e.g. burn a new copy of a working Linux distro which would fix the situation permanently. Obviously, this doesn’t work for the distros that use lilo instead of grub, but most popular distros use grub today, including Ubuntu, Fedora Core, and SuSE.

Note that the numbers in (hd0,0) represent the drive number and the partition number, both starting at zero. So if Windows is e.g. on the second partition of the first disk, use (hd0,1) instead.