Here's what I do when I have an infected Windows machine, and it's always worked for me (so far).
Download and install Spybot Search & Destroy. Don't click any of the add-ons unless you think you really want them. Once installed, do an update to make sure you've got the latest files, then do a scan to see what it finds.
If you've still got problems with your machine after using Spybot, I recommend you download/install/run Malwarebytes.