No problem.
For "perfmon /rel":
Press WIN + R keys together and the Run Window will open.
Then in the Open box type in "perfmon /rel" without the quotes.
What you will see is a dated performance history. Errors will be red circles with a white plus sign inside. You can click within the dates to see more details.
MMC "error" - here is one possible fix even though it relates to Windows 10:
http://www.kapilarya.com/mmc-could-not-create-the-snap-in-windows-10
May or may not be directly appliable within Windows 7 but does seem to include that version.
You can google the error for other possible solutions and even some YouTube based explanations and other fixes.
As for proceeding - simplest to more complex is the order I like to follow whenever possible. "Simple" being relative so do what you feel most comfortable doing first. In your situation I would first try shutting down one of the AV programs. Then, if necessary, switch them around. Maybe even try a brief test with both off.
Understand "Ancient History". No apologies necessary. I worked with FORTRAN and punch cards. Lots of BASIC (via yellow paper tape "storage") on mainframes. Plus Apple PC's, Commodores, Atari, early IBM PC's. US Robotics modems and land line connections. Monochrome monitors - things that I am sure are shared by many other forum members....