I agree that AVG is very good, even better as it is FREE, but my new PC came with Nortons and I have been using that with no problems so far, but if anything came to light I would be straight back with AVG.

Spybot Search & Destroy is also a another must have program, again FREE and worth it weight in gold. As it is primarily designed to find and eliminate spyware & addware I also have Winpatrol with Scotty the watchdog who barks & flags up any new processes that have installed themselves. Again this is FREE & falls into the must have category.

Add Zonealarm firewall, (again FREE) & I reckon I might just about have all bases covered.