Yes, this all started because:
1) I was running Norton and on Internet Explorer, I kept having problems that I could not connect and got a message, Server Not Available. A friend said this could be Virus.
2) Problem persisted and friend also put on AdAware and Spybot, found a lot of problems, but Server Not Available persisted.
3) Sunday Times said Adaware and Spybot can conflict and recommended Download.Com, which I went to and it said AdAware and Spybot good, but recommended Avast, which is how I have gotten to where I am.
4) Computer friend then added AVG as he thought it might solve problem, but it just keeps coming up saying Back Door Agent BA, but it can't take it off.
I know this sounds like a dogs dinner, but I know nothing about computers and when I went to 2 real computer companies here, one blamed Avast, the other said, don't know anything about Avast, get in touch with the company itself, which is what I have been trying to do.
Hope this helps, Cheers Leslie