While you can do no harm by running the "scan on demand" components of two or more anti-virus programs, we do not recommend more than one "real time" anti-virus scanner. There are several reasons why you should not do this. First, running more than one anti-virus program in the background will unnecessarily tie up significant system resources. Second, there is a possibility that the programs could conflict with each other, preventing one or both from working properly. In this case you might be left with no virus protection at all. Third, if you have a good anti-virus program like Fix-It Utilities 2000, you can rest assured that you have the best protection available. Using another anti-virus program along with it is only likely to cause trouble. Therefore, we recommend that you choose an anti-virus program that you like and stick with it.