I went the other way because AVG had become intrusive and slowed down startup times considerably.

I don't use Windows on my own machine, I got rid of it and went over to Linux but my wife uses Windows Vista - which is pretty dire IMHO - but she is reluctant to let me install Linux - doesn't like changes and having to do things differently.

Panda is much less intrusive than AVG as all the virus definitions are held on line and has had some pretty good write ups.