An update to Comodo Internet Security this morning has caused a few problems with cmdagent.exe using 100% CPU cycles has now has been fixed..
Anyone with the problem, the solution was posted here:
Page 3 post #35
we have issued new base which fixes the problem
for those who already have the problem - here is workaround:
Boot in safe mode
remove c:\program files\Comodo\Comodo Internet Security\scanners\bases.cav file
start diagnostics (don't mind red status and not fixed issues - they are because of safe mode)
your AV bases will be 1 version
Update it to the latest version again
the problem should gone
I had the problem myself and found out it was comodo, and a few friends got in touch with the same issues.
All fixed now, though was a pain to sort it initially.
Hope this helps