Something went funky when I installed updates to QT/iTunes yesterday to XP on a Dell machine. I was then going to uninstall both and reload, but I don't know how to uninstall QT, iTunes uninstalled just fine. Even in the Add/Remove Software control panel, the removal of QT was not successful either. I tried to just re-install QT but I keep getting an installation failed -3 error. However, QT appears to run fine anyhow. Word also has a problem when opening, saying it has a problem that needs to be repaired. Not sure how to do that either. It won't let me do it from the installation CD for some reason.

Is there something in XP that is an OS X equivalent that allows you to "Rebuild Desktop" or "Repair Permissions" etc... in attempt to fix weird behavior?

Have Dell GX260, P4, 2.0 GHz, 1 GB RAM, 80 GB Drive less than half full. XP Pro fully updated.

Use system restore to turn the system back a few days to a point prior to when you made the bad install, it will restore it to that point in time. (Programs-->Accessories-->System Tools-->System Restore)

Also to note...this will not erase any files, etc. on your system, should you use System Restore (which I would try, as well).

It only reverts some installations...system changes...etc. So any new files you may have added, modified, etc...will all be fine.