Hi:
EDIT: OOPS! Sorry, @whs, I didn't notice that you had replied.
First, Malwarebytes Anti-Malware (MBAM) is
not an anti-virus and is not a substitute for one.
So, even if you choose to run MBAM Premium for real-time anti-malware protection, you'll still need an AV, either free or paid.
(MBAM (Free and Premium) does still support WinXP. However, some users on
very old hardware run into issues, and new features (such as anti-ransomware) will not be supported on XP.)
There is no one "best" AV to suit all computers, all users and all budgets.
MSE is probably as good as any other free AV, though it has both fans and detractors.
Having said that, many of the "free" AVs come with a "hidden" cost, in terms of marketing popups, intrusive toolbars, reduced features/configuration options, and/or reduced support, etc.
Moreover, the cost for a robust, paid AV typically works out to pennies a day (or less). That is probably no more expensive than the cost of a game and is likely far cheaper than the cost of time, effort and lost productivity expended to recover from a malware catastrophe, data breach, identity theft or other mishap.
EDIT: This product is not supported on XP.
Having said that, Sophos currently offers a new, free AV for home use.
I have not evaluated it, so this is mentioned "as is".
More info here and here.
>>To answer your specific question about "multiple AVs", the answer is: NO.
There should be ONLY ONE installed and running AV on the system.
Installing multiple AVs is asking for trouble: clashes, conflicts, slowdowns and other performance problems. Doing so will REDUCE, not improve, your security.
>>Do not confuse "multiple AVs" with a "layered" approach using different applications with non-overlapping jobs (e.g. anti-virus, anti-malware, anti-exploit, customs hosts file, etc.).
>>Having said all that, the most important computer security component is the one between the chair and the keyboard: practice of "safe hex".
Cheers,
MM