Crashing & closing down

[Insane Wally]

How do I solve the following:

a) internet sites constantly crash

b) when closing down programs (anything from ms excell to internet pages), they remain on the screen - the program has closed as it does not appear on Windows Task Manager, but the last window is still on the screen (hope that makes sense)

[Ernzoa]

Try using the defragmentator, then do a few virus scans (if you dont have any antivirus, download AVG free, its pretty good) and also do an antispyware check with microsoft antispyware or whatever antyspyware software you have. If it's still acting funny, I'm afraid you'll need to do a system restore (unless you have a ghost copy of windows backed up somewhere)