Carol - There is a free program called Spybot that you can download that may be able to fix your problem.  If you don't have anti-virus software like Norton you should get it.

There is a free Antivirus software that is pretty good. go to www.grisoft.com  the name of the program is AVG. You can get updates to the virus definitions just like the pay programs.

If you find out which particular virus you have, by name. You can always go to the home site of Norton Antivirus, www.symantec.com .  They offer free repair solutions to many virus and worm problems.