I think you should say something about the repair console in XP. If you go to that, it will bring you to a command line. I'm not entirely sure as to what extent you can use this, but I have found it useful in alot of cases. You can rewrite a master boot record through it, among other things. But if you do not know what you ar doing, stay away from the repair console. It is quite intimidating for most people. Doing the steps on that website just do an over the top install of XP, which just reinstalls everything. Will fix most all of your OS problems.
