How can I get rid of a Windows pop-up?

All of a sudden on the right of my taskbar a red circle with a white x inside it is popping up a warning dialog box that tells me “Your computer is infected! and goes on to say I have a spyware infection. When I click ont he message nothing happens. I have spyware remover (AdAware) but I do believe its a Windows message ………so how do I stop this annoying pop-up?

This is a bad sighn of a Trojan virus. Check out these sights bitdefender/Mcafee siteadviser all free. I bet its in the addremove look for it.

How to diagnosis and fix windows xp registry & startup errors

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