You may just have some protection software in conflict.
I see Adaware 2007, Superant antispyware, McAfee full install, Symantec, and Windows Defender, together with a great deal of other software that make a lot of demands through the processes. Thus too many demands, potentially, on the task manager.
I would re-evaluate you security settings and installs, and perhaps remove either the McAfee or Symantec install - because one usually has difficulties when both are fighting each other over the honor of defending you. I would also consider removing Superant as long as you have McAfee... then see what happens
I would also run a simple registry edit such as RegCleaner to be sure you got everthing off of the one you removed.
I would also look at your installed memory, which you didn't mention, to see if you really have enough memory for all that software you have installed... and take a look at your processes to see how many programs are attempting to run.