IF you can identify the malware/virus you can usually find a dedicated removal tool from symantec or another anti virus company. Also, try running anti vir from avira. Adaware is also a good piece of software.
Winrar isn't a virus. There is a good chance you downloaded Winrar from a bogus server, though. If you get a pop-up saying to download blah blah to clean a virus, close the window. It is false and 99.9999% chance that if you click something in that window, you will get a virus. http://www.mozilla.com/en-US/firefox/ Never use IE under any circumstances unless it is impossible to avoid. Copy-pasta the URL's if you must.
