sounds like you need a good cleaning.. (an upgrade to win7 would be good for you too.)
run dusk cleanup, then run clean-up system files/(click on) more options tab, clean-up system restore copies and shadow copies,
return back to back clean-up, select options in box, then click OK, delete files.
it be nice to have a registry cleaner to go along with it.
try free ccleaner..
also go into internet options in the control panel if not in (IE) and empty your history, cookies and cache.