well in terms of what I'm running consistently; it's just avast and Zone alarm - the others I've just run to try and get rid of existing malware that avast couldn't remove / detect.
I've defragged recently, so that shouldn't be an issue.
I'm wondering if reinstalling windows is the way to go, although that will involve quite a lot of time to get everything back to how it is now (i.e. Service Pack 2, office) etc etc.
Frank - I've got rid of Freeram XP Pro. I've run Ashampoo Winoptimiser in order to check that there's nothing amiss in the registry, but I'll check out Tuneup utilities.
BTW, am I correct in thinking that I should only run either Avast *or* Ewido at one time?