That might not be enough. Some antivirus are so defective, that they still interfere even when turned off from their interface, and the only real solution is to stop their services, or uninstall them. I HAVE witnessed this first-hand on many user's system while doing live sessions to support them and yes, it happened several times. And, some users don't realize they have two antivirus running, like a real antivirus and an anti-spyware, and in this case they should be both disabled.