I just made a topic about a month or two ago about this. Download AVG Free 8.0. It leaves an annoying process that you can't end in the task manager (which eats up anywhere from 5,000k-45,000k of memory), but it works well. Also, download Malwarebytes Anti-Malware.
My comp was pretty much as close to fucked as it could get, but it's perfectly fine now.
E92 335i: Space Grey|Coral Red|Aluminum Trim
Future Ride: 2015 Mustang GT Premium |Guard|401A|PP|Recaros|6MT