What does this error mean? I cant fix it. Help asap, TNX

I get this error when ever I close any application on my comp. besides this error I haven't seen any big problems with my comp, yet at times maybe some slow downs. But nothing a reboot could not fix.
at first I thought it was my ram, so I swapped out my ram. that didn't fix it.
I then went to stock speeds and didn't over clock. that didn't fix it.
I then did a windows xp repair, which replaces a lot of the system files and stuff. Just about as good as a reinstall. and that didn't fix it.
I also reinstalled my video card drivers and updated every other drive on my system + window update.
But nothing is fixing it. What do you think could be the problem?
Thanks!
-= LANmaniac =-
www.LANmaniac.com
24hr SoCal Gigabit LAN Party
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