It's been a while since I last tested the paid version of Emsisoft Anti-Malware (EAM, formerly a-squared anti-malware). I've always used the free version for years now, and recommended it as a "second opinion" on-demand scanner. I'm impressed with the "quick scan" (taking only a few minutes) and the low incidence of false positive detections.
The paid version differs from the free version in that it includes real-time protection, and auto-updates. My understanding is that it includes 2 anti-virus engines. And therein lies the rub. Is EAM an anti-malware, or an anti-virus? The distinction is increasingly blurred.
The last time I tested the paid version (as a-squared), it co-existed quite nicely with whatever AV I was using at the time. So I recently installed EAM (paid) on my XP/sp3 system, alongside my resident AV (avast! Free 7.x). My results:
The download is 231 MB, and the installation went smoothly. I received no alerts about any incompatabilities. It seemed to work well in its on-demand scans, and auto-updates. It did not slow down my system or browsers. As always, I cannot comment on its efficacy at protection, other than to note that it never detected or alerted me to anything. In short, it proved trouble-free in actual use.
However, when I opened the program, I noted that 2 of its 3 layers of protection were turned off: namely its Behavior Blocker and Surf Protection modules. Only its File Guard module was working. Furthermore, I could not activate the 2 non-working modules.
Now Emsisoft provides an excellent support forum, and I worked with their support staff to resolve this. Unfortunately I could not, and eventually had to uninstall EAM (in Safe Mode) when it began freezing my system after attempts to repair it. At one point I even had to restore my system from an Acronis back-up image on an external HD.
I'm not sure where the conflict lay, but suspect it was with either avast! or my OutPost firewall, or possibly with an 8 year old OS. I cannot rule out user error. I've always used a resident Anti-malware along with my various AVs without problems (apart from MBAM Pro slowing down my XP) until now.
My experience might well be unique, and I only post FYI. Meanwhile, I'm reverting to Windows Defender (the original free anti-malware designed for XP/Vista/ Win 7) for this system.
I continue to have faith in EAM, but question whether it is wise to run the paid version along with another resident AV, at least on XP systems.
