Question : Copy & Paste Stopped Working. Help me

My clipboard suddenly stopped working without reason.
Nothing happens when I try to copy or paste.
It's not the keyboard's problem.
Pasting with the mouse(Edit>Paste) doesn't work either.
I've installed Windows SP3 and Zone Alarm Firewall to fix this problem, but neither worked.
Do you have any idea?

Thanks

Answer : Copy & Paste Stopped Working. Help me

Hmm, the only thing I can think of is open msconfig, click the "Startup" tab, disable all items, and restart if you still have the problem, reenable the items. If you still have the same problem reopen msconfig, click the "Services" tab, click "Hide All Microsoft Services" and click "Disable All" and restart your computer to see if you still have the problem. If you don't have the problem, reenable each item until you get the problem again and then you'll know what's causing the problem. Also, maybe disable this:
O2 - BHO: Windows Live Sign-in Helper - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files\Common Files\Microsoft Shared\Windows Live\WindowsLiveLogin.dll