the only reason other AV's were suggested was purely because the OP has Win2000.
Yep!! Btw: for Win2000 and WinXP I still use AVAST! 4.8.1368.0 (full pro; with a one year free license – just register normally on the website by email request; registration code for new avast is working on 4.8!) – and I really love the on-access-scanner-messages always popping up in the right lower corner of the display; that's very useful for seeing what's going on ...
So please AVAST!-guys: don't let AVAST 4.8 die and please make it downloadable again on your website!!! It is still the best AV-solution for people who are aware where they surf to (i.e. avast 5/6/7/8/9 might have more protection schemes, but basic protection is there – and that's the most important thing).
Btw: the only issue is some lowered responsiveness while updating; but with the setting "ask when update is available", you can postpone update to the first best situation you can afford it and are not bothered by a blocked PC; that is done best some minutes or even seconds after that (beautiful) small green popup. And also the updating window is not too big (as it is in the later versions). The only unnecessary thing is the focus stealing nag screen popping up from time to time ... AVAST! 4.8 still has best design of all the versions since then!