|You only have 1 AV program installed don't you?|
Can I run more than one anti-virus program? Anti-spyware program? Firewall? Should I?
Real time monitoring, on the other hand, is another story. When you install most anti-virus programs they often automatically install and enable their real-time monitors. Running two or more real-time anti-virus monitors at the same time is very likely to cause a conflict. That conflict could result in error messages, crashes of the anti-virus programs, or other types of failure.