I got rid of McAfee years ago (it was free with my Comcast) when it slowed down my system so much the machine hardly ran. I now use the Free AVG you can get at download.com . The 100 million people that have downloaded it can't all be wrong.

Sometimes there is nothing you can do to get rid of the worst viruses except reformat the HD and start over. If your machine still works I would save whatever you can ASAP. Before reformatting you may try a restore date prior to getting the virus but it may not work. Good luck.