A few months ago I had a customer (2 XP machine on a peer to peer network) who couldnt log into one machine from the other. He kept getting the message that access was denied. I did a scan with NOD and found a virus (can't remember which one) but it was removed and problem was dealt with (or so I thought). However, the access denied message continued and it wasn't until I did a Goggle search that I found the answer - the virus had changed a registry setting to prevent access to shared folders from other machines - I found this through Symantec's website and corrected the problem. Does NOD correct registry problems caused by viruses?