Many common malware programs produce this effect, as they attempt to frustrate any efforts to remove them. Can you say if you had a firewall running? If you had no protection (firewall or AV) then possibly your machine has one or more common viruses. I agree with So-crates that, in your case, it would be best to get someone more experienced (e.g. your local computer fix-it guys) to give your machine the once-over. Some of these can be troublesome to remove.