For over a decade,
I have learned from many computer sources whom I trust, NEVER run too Anti-Virus programs, side-by side! You should completely REMOVE ANY COMPETING AV PRODUCTS FROM YOUR SYSTEM before installing new AV. Some even recommend going to the manufactures website to get the uninstall removal tool, AFTER you remove the competition from Add/Remove programs:
Read the info about how to use the uninstall utilities first. Use them AFTER Add/Remove programs if you have trouble with Add/Remove programs getting the software off your system, or if you just want all fragments of a past AV program removed. Than run the removal tool for your competing AV program. This will remove the competing product completely from the system:
http://uninstallers.blogspot.com/You CAN use an on-Demand Malware scanner. The only one that I would recommend would be Malware Bytes Anti-Malware. The free version requires an update before it is run each time, but is a good line of defense. If you want resident (real-time protection) you can pay a one-time, lifetime license key purchase of $25 USA money. MBAM for short, runs beautifully with Avast. However, considering the excellence of Avast 7's protection, especially with always up to date streaming definitions for File Reputation and Cloud Service updates released instantly. Avast is, or will likely soon be doing just as good as the paid version updates for MBAM for real time updates.
I just use Avast 7 Free, and the free version of MBAM. You will eventually get conflicts and slow-downs with two AV's on your machine at once, if not right away, eventually. No problems with Avast and MBAM.
A question for anybody? How often does MBAM update in the pro version? Avast wants to get the cloud and file rep services updated 20 times a day.
Jack