Help!!!!  I have 2 computers.  This one is fine.   The other one which is used by my husband somehow (hmmmm wonder how...) got Winantivirus Pro 2007 loaded on it.  Then, everytime you turn on the computer, it automatically goes to an error message saying Winantivirus at the top and the error reads "product already installed. would you like to proceed with downloading?" Then it has yes and no.  Neither key works.  Then the computer locks up and won't do anything.  I have tried to go in and go to msconfig and go to safe mode but I can't even get there.  This is a Windows XP system.  Any ideas?  

If you have the Recovery Console installed, you may be able to repair the problem from there. This program is probably running as a service, you may be able to disable it. If not you may be able to delete the program. Chkdsk might solve the problem. For information on the recovery console see this page.
http://support.microsoft.com/kb/314058

If the above doesn't work...
Hopefully you have a backup of any important information on this computer.
If so, I would format the hard drive and reinstall WinXP.
From what I could find, Winantiviruspro is a malware program that is extremely difficult to get off your computer. See the following page:
http://forums.spybot.info/archive/index.php/t-12290.html

If you don't have a WinXP CD and the installation key, you will have to invest a lot of time and effort to remove the infection from your computer

I will try the suggestions.  I may have a couple of questions for you regarding your advice.  But, thank you.-D

Be sure to disable Win XP restore mode. If you do not it will reinstall the malware on each reboot. It sounds like the computer defenses stopped the malware but restore may be trying to reinstall on reboot.

   You could try holding down on the Shift key during startup.  That prevents startup items from starting.  Hopefully, that would get you into Windows where you can try to get rid of the malware.