(03-01-2015, 12:36 AM)surferdude2 Wrote:(02-28-2015, 11:42 PM)me50 Wrote: So, the big question is, can I have Trend Micro and Defender at the same time?
No. If you install and run two different AV programs at the same time, you will be vulnerable to attack and have performance issues as well.
I don't agree with the idea that two different AV programs make you more susceptible to attack in general, but it is very common for two AV programs at the same time, they may cause performance problems, so it's usually not a good idea.
BTW, malwarebytes free is different because you install it and only run it when you need to check something. It doesn't scan for malware when you run programs, only when you run a scan. You need a full time antivirus in addition to malwarebytes. It's usually OK to have both malwarebytes and another antivirus program on the same computer.