Malwarebytes' Anti-Malware

This program is absurdly simple. It detects and removes difficult pieces of malware. It has my vote.

running a scan

1. First thing you want to do is make sure you're up to date with the latest definitions. Click on the Update tab.
2. Hit the Check for Updates button.
3. Click on the Scanner tab.
4. Select Perform full scan.
5. Press the Scan button.
6. Find something else to do while the scan occurs like digging half a hole or photographing the wind.
7. When the scan is done you'll be alerted with a box. Hit the OK button in it.
8. Click the Show Results button.
9. Hit the Remove Selected button to get rid of the detected malware.
10. Notepad will open displaying the scan log. Unless you're interested, close it.
11. Exit the program.