Avast also protects from some script/web bugs, malicious site access, rootkits, and some spyware. On another note, yes, it does protect against and remove trojans.
Go to Avast.Com and download Avast Home Edition (Free) for PC. Install it and restart your computer when prompted. Go back to the page where you downloaded it and "register" for the free registration key, (they don't contact you. All they do is send you the key via email), and then enter it into Avast. Update, scan, remove the malware, done. Avast will also auto-update every time you log in or restart your computer. It is a well-known program and I use it on ALL of my PC's and my Mac. It works great. It's real-time protection is included. I highly recommend it. It's also very well known and widely used.