i just install pc tool with paid version 2011,n all my computer sytem freezing,slow everything,i did try figured out for a few hours,… ???
so i decided to uninstall it,back to free comodo,N my system back to normal,… 
after i checked in their forum,so many ppl complained about that,… :-\
Welcome back 
Join the club. I bought pctools spyware doctor at the end of 2010, everything was fine then. When it upgraded to the 2011 version (about 2 months of use) then ALL of my security software was now incompatible. (freeze ups and crashes) I called pctools tech support by phone and they said that I need to uninstall CIS and purchase their AV plug. So I uninstalled PCtools after 2 mo. of use. I reinstalled it a couple of months ago and it seems to work fine now, but I found that I had to uninstall the browser defender toolbar that installs without your consent. I’m very disappointed with them. :-TD
Another free tool destroyed by Symantec…