Lets talk Security and Optimizations

[Oink_mR]

BitDefender and Malwarebytes best combo

[mIKe]

If you get something really nasty run this, it works wonders.

http://www.bleepingcomputer.com/download/combofix/

Also is good for the inevitable friends and family who ask for help because they can't refrain from downloading everything in sight.

[gamethan]

I've had kaspersky security like, all my life and it's worked pretty well. takes up some processor power, but if you need it you can simply turn the entire program off at the click of a button.

[Ngugu]

I do sorta the same thing as mike. I just keep Defender up to date constantly, and occasionally use Malwarebytes or AVG just to make sure I don't have anything that Windows can't detect. It's worked well for me so far.

For regular maintenance, I defrag my HDD occasionally, go through all my downloads and crap and delete stuff I no longer need, etc.

... Defender still exists?

I use MS Security Essentials and Spybot