KDE has this thing where you can select which operating system you wish to reboot into. When logging out there is a drop-down labeled "Restart Computer". Click and hold this and you'll see a list of options for rebooting, depending on your Grub/Lilo configuration. This option itself is configured via the KDE Control Center (System Administration/Login Manager).
The other day I thought it might be nice to boot into Windows to play a bit of Titan Quest, which is a kind of a Diablo clone with nicer graphics, and I thought I might try the aforementioned KDE feature.
Well, it was funny to the degree that Grub failed to boot windows, indicating instead that it could not read the disk. Bugger. Just like that I said "Bugger", except possibly with an exclamation point or two.
At this point I figured that the ancient 80GB drive on which Windows was located had failed, and rebooted into Linux. Well, attempted to. Same error. Bugger. Again. Probably not a hardware failure then.
I briefly cursed KDE for somehow hosing my Grub installation, then set about fixing it. In the past I have repaired this kind of thing by booting a live cd and running grub-install from a chroot. This works just fine, but is not entirely trivial unless you're some kind of brilliant computer guru such as I. Well, I don't like to brag, but.... Actually, I do like to brag, so cancel that last bit...
Anyway, it just so happened I had a copy of the Super Grub Disk lying around. Oh, no reason; just because I thought it looked interesting and definitely not on account of my having recently needing it to fix a Windows installation I had accidentally destroyed. No, no, nothing like that at all. Did I mention I am a brilliant computer guru guy and totally unlikely to do anything stupid like that?
So, in goes the SGD, ctrl-alt-del to reboot, up comes the Super Grub Disk menu, select the option to boot my Linux installation, wait, log in, type "grub-install /dev/sda" and it's all fixed. Dead easy.
In fact it can be even easier, on account of the SGD includes an option to automatically restore Grub on the MBR, for those less capable than myself. Did I mention I am a brilliant computer guru guy? Well, I may be a brilliant computer guru guy (and I am) but those blokes who dreamed up the SGD are, like, rad man. Check out the features here if you don't believe me. At 1.7MB for the download, and fifty cents for a CD, can you afford to be without it? (The answer is no, in case you were wondering, because I know many of you are a bit thick.)
BTW Notice how I have bravely resisted any mention of superheros (Super Grub Disk - get it!). This is because I am all mature and stuff, like a fine wine, or a turd.