Hi, YMF!
Is there a BIG problem if avast4 works fine in most W2K computers but have some problems with others? Avast4 home works fine in my two W2K Professional computers and I have also many friends using avast4 and W2K without any problems at all. We are all connected to Internet with fixed line. If you use dial-up connection, then maybe your problems are associated with it?
I believe that Avast development and support can fix your problem. Maybe this slogan I have heard many times may help them with their efforts: We make miracles immediately, mission impossible takes a little bit more time…