After installing AVG 8 a couple of months ago, I found that one of its new features, the link scanner, was slowing down by search results by trying to scan every link on a page. I found directions (which were a bit involved) on how to install it without this feature. I have heard, however, that they have now fixed problems with this feature--not that I really want it anyways, Firefox already does this. Anyways, if this sounds like the problem you are describing google it or let me know and I'll post the link to the directions in a reply. I'm assuming however that you are talking about a recent installation, which should have fixed the problem. If you are using an older .exe, you might want to uninstall and try with a newer one.
when i install avg 8 i get a notice saying before install i should upgrade roxio as this may have a bug in it, when i do install avg it slows down the pc incredibly