You could have a nasty Virus. My brother-in-law had one that the Verizon Suite would not clean. Took me hours to fix his PC. I use another software program.
Check for this. It is not an easy one to get rid of. I had to boot in safe mode and do a few other things with third party software.
See info here.
http://www.wiki-security.com/wiki/ms_Parasite/Antivirus2009
Antivirus 2009 is nasty software that the Verizon Suite did not find at that time, or could not get rid of.