Posted 13 October 2007 - 10:21 AM
There are two problems with having more than one Anti-virus on your computer.
1). You must be careful to have only one application running real-time protection to avoid major system conflicts as well as computer sluggishness. This does require some user discipline.
2). You must be very careful to review any malware found by one AV, because these may be part of the other's definitions file, etc..
A careful and cautious user of the Internet probably only needs one resident AV, whose real-time protection will cover most of the current malware. Moreover, there are several very good on-line AV scans that can be used as a double-check, thus avoiding the pitfalls of duplicate resident AVs.
Whereof one cannot speak, thereof one should be silent.