If you know a -safe- way for other people to remove those nasty icks the internet likes to put on their computer, post it here!
These are the ones I know the best because I've used them before and I -highly- recommend them...
It's a free online scan that checks every spot on your hard drive and can catch things other programs might miss.
The free download works just as well as the version you pay for... If you use this one, I suggest updating it before you run the scan, as they update the definitions database regularly. I use MalwareBytes on a regular basis, once a month is good enough for me, and it scans every drive on your computer. Even if you have an external hard drive hooked up to your USB port, you can scan it!
I strongly advise AGAINST using Norton 360 as it does NOT catch everything and actually bloats your computer! Norton is a system hog and steals most of, if not ALL, your available resources, just to run in the background! You don't need something like that.
I myself use Kaspersky Internet Security along with MalwareBytes, CleanUp and Mozilla Firefox. (You can also use Google Chrome if you want... It's a good browser if you don't like Firefox.)