Microsoft Security Essentials

How good is it?

I honestly have no idea. I've been using Nortan Anti-virus (Yeah, yeah. System hog. Low detection rate. But it came with my notebook package), but my subscription is running out. I need a new anti-virus. I'm hoping for some suggestions for some good anti-viruses. I already have Malwarebytes installed.

Yeah its decent. I'm using it and have it set up to only scan stuff that I download from the internet otherwise it bogs my computer down by constantly monitoring processes.

I have been using it for months and I have had no major viruses infect my PC.
I have however had small viruses get into my computer periodically but it takes
care of it fast.

I recommend Spybot S&D and possibly ThreatFire. Both are free.

One thing about Spybot S&D is that it encountered a virus called virtumonde.prx and it couldn't fully delete it from my system. It wasn't until I got Stopzilla that it got rid of the virus, but I don't recommend Stopzilla because it slows your system and Internet browser like crazy.