My advice is, if you get one of these viruses, scan first with your installed antivirus, then try going to either trendmicro.com and doing on online scan there, or pandasoftware.com and use theirs. Both of these will scan deeper than your antivirus and will clear the virus off for you.
However you'll find that most of these viruses are in your temporary files, which you can clear yourself by going to your control panel, internet options and then temporary internet files. This isn't guaranteed to work, so I would do this and then check it with a scan afterwards