I have had some problems with my computer being slower than usual.  Also, when the computer goes on the mode where the screen goes blank after the screen saver has run the prescribed time when I move the curser or type on the key pad the screen remains blank and does not come back to normal.  Only after doing control alt delete and waiting 30 seconds do I get my screen back.  When I checked the system processes my CPU usage was 100% and it was all devoted to explorer.exe  .This problem seemed to happen after I visited a website where I viewed a database of information from a company offering sample cases to prepare for an exam.  A window popped up saying my computer had errors on it and I was to run WinFixer 2006.  I clicked for information to start to download it and my internet security warning boxes started to pop up asking if I wanted to permit it.  I have McAffee Virus scan (provided by verizon) and also Nortan (this came with my computer and the subsciption has expired but is apparently still running - I am working on a project right now and do not have the time to figure how to uninstall it).  I ran the McAffee virus scan and it found and removed two things ( I think a PUP and trojan?).  I also did a search and removed cookies that said Winfix since a search on the web said this may be a virus and not something that was a warning from my computer.  I did another virus scan with McAffee and it did not find anything and a search for winfix did not reveal anything but I am still having some problems - particulary when doing work online.  When I went online today I got a popup saying "Warning, your computer may have critical errors in the registry..." which came from the web address www.winfixer.com/download/2006/...  .  Do I need to download this to fix my computer?  Is this a virus and if so since my virus scan did not detect anything am I safe or do I have a problem since I am getting this popup (I think my popup blocker is on and I am still getting this)?  Or is there something else going on?