I have a system alert on my pc even though it is fully protected. Why?

When I click on it an ad pops up for different anti virus programs. I have scanned with panda an it say's its all clear.

I have a system alert on my pc even though it is fully protected. Why?norton internet security

Panda isnt picking it up. Try these, both free.

Spybot - Search %26 Destroy detects and removes spyware, a relatively new kind of threat not yet covered by common anti-virus applications. Spyware silently tracks your surfing behaviour to create a marketing profile for you that is transmitted without your knowledge to the compilers and sold to advertising companies. If you see new toolbars in your Internet Explorer that you haven't intentionally installed, if your browser crashes inexplicably, or if your home page has been "hijacked" (or changed without your knowledge), your computer is most probably infected with spyware. Even if you don't see the symptoms, your computer may be infected, because more and more spyware is emerging. Spybot-S%26D is free, so there's no harm giving it a try to see if something has invaded your computer.

http://www.spybot.info/

http://superantispyware.com/

SUPERAntiSpyware is the most thorough scanner on the market. Our Multi-Dimensional Scanning and Process Interrogation Technology will detect spyware that other products miss! SUPERAntiSpyware will remove ALL the Spyware, NOT just the easy ones!

Easily remove over 100,000 pests such as SmitFraud, Vundo, WinFixer, SpyAxe, SpyFalcon, WinAntiVirus, AntiVermins and thousands more!

I have a system alert on my pc even though it is fully protected. Why?spyware remove

check the firewalll as well
The pop-ups may have come bundled with something U recently installed. Check the name and source of the pop-ups.
well try some anti protetion programs