Look for a free virus scanner online, do NOT download a scanner. There are enough free ones you can use without having to download them. Once you locate the infected files, write down their locations on your hard drive. After that, boot into safe mode, find and delete those infected files, then restart normally. If this can't get rid of them, your best bet at that point would be a hard drive reformat.
As for anti-virus programs such as Norton, McAfee, etc, they are pretty close to pointless. The only benefit from them is the virus scanning function, which can be had from many other places. Such programs only "protect" you from viruses that you have definitions for. If you have a definition for it, that virus is pretty much obsolete, and there are already new ones circling around the web. The illusion of protection that these anti-virus programs offer are laughable. Why pay for, and let hog your system usage, a program that only informs you that you have a virus after getting it, rather than protecting you from getting it period?