Computer wants to restart right after loging on

I'm running WinXP SP2. I have AVG running, and use Ad-Aware and Spybot 3x week. This problem has been going on for about 2 months. I turn on my PC, logon and shortly after it loads windows and my desktop, this box pops up:

"Restarting your computer is required
The computer must be restarted before updating can continue. Would you like to restart now?"

If I click "yes", Windows restarts and again the same message pops up.
If I click "no", the message goes away, nothing happens and I don't have any problems running any programs.

Has anyone experience this? Should I just ignore it and continue to click "no"? Or is there something that needs to be fixed?
Thanks
Sunmaiden

 

I would guess the answer lies with AVG. I stopped using it after the last upgrade, it kept trying to upgrade itself after it had already been upgraded. I bought a commercial version of a security suite with a license for three machines, and then also used it on the other two. Comodo is a great free firewall, and Avast! Home Edition AV worked well for me.

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