I recently installed NIS 2011 via Comcast to give it a try as a replacement for Microsoft Security Essentials (which was relatively painless but recently reviewed as inferior to NIS).
My computer has an older single processor and my ccsvchost.exe lockup problems are not 50-60% but 100%...and when I say "lockup" I mean "LOCKUP". When it enters this mode, I might as well go for a walk as ANY additional computing is precluded.
I was familiar with "Process Explorer" long before I ever installed NIS and it does document the lockup as advertised...but understanding the "stacks" report etc etc is far beyond my ken.
I will be following this thread with interest in the hope that some resolution to this problem will be forthcoming in the not too distant future. If not, this problem will likely send me back to MSSE where, though perhaps less protected, I will at least have a semi-protected computer that will function when I want it to.
In the interim I have de-selected "Spam" protection and "PC Tuneup" to manual. Hopefully that will mitigate the re-occurence of this lockup problem.