elanya

That thing should still be capable of running fine.

When's the last time you actually wiped and reinstalled windows? It may be a lot of work, but that might be your best bet. I would stick with XP; there's no need to go so something newer/bigger/lamer. If you have a product key, you can borrow anyone's CD, or get a cracked key/full cd off the internets (I can arrange that, if you need).

What you'll need to do, since I presume you can't format your hard drive without losing the non-windows data on it, is install a fresh version, from cd, in a new directory (name it something like WinXP), and then install any apps you like freshly as well. Then delete your old windows directory. This is less ideal than formatting the drive, though. If you can offload your precious data to the external or something and format before reinstalling, that would be best.