CPU 100% drops below 3% once task manager is opened

There is a conspiracy theory for you. Right out of the NSA handbook

Serious as a heart attack and kind of spooky: When CPU usage is just high (50% to 60%) and I open Task Manager, it's usually McAfee on access scanner at work because I've just clicked an emoticon or something like that. Other examples are service host -- some long winded process I can't always find in the TM list to get the name right.

But when it's 100% and this has happened consecutively for over half a dozen attempts to find what spikes this, I'm dead serious: CPU usage has dropped immediately to under 3%. Yesterday and today I've "caught" this thing 2 times. CPU usage drops so fast you can't see what spiked it.

There are 2 Google Ads that pop in right about here but don't show up when I edit the post.
These do not work, find hundreds of non-existent "errors" so that you'll buy the program and then when you run it
you might get less than half a dozen errors fixed. Don't trust these programs, I don't. I have no control over what Google Ads does but I'd call it anything but "Adsense" to be honest.

I had Norton trial as the default AV when I first fired up and set up the laptop but I'm a McAfee person so set this up and removed Norton during the McAfee setup process. So it's not likely this is an infection. I apply all updates as soon as I see them, if I'm working and can't quit at the time an Update notice comes through then it's no more than overnight that these are applied.

Is there some Trojan that does this? Does anyone have similar experiences or better yet -- is saner than I am and proven this is not some NSA trick? But hey, just because you're paranoid doesn't mean the NSA isn't leveraging your CPU power or otherwise out to snoop on you.

Please see these threads at Sevenforums and see if your problem is related to these:
Solved CPU stuck @ 100% unless task manager is open - Windows 7 Help Forums
Solved CPU behaving strange, running at 100%, unless Task manager is open - Windows 7 Help Forums
Solved CPU Usage @ 100% - Page 2 - Windows 7 Help Forums

To: The Veterans,

Thanks but this didn't seem to be it. I don't have the .exe file in either of the directories nor is there a Search Indexer service.

So ... what ever is happening here is new to Windows 8. Or, McAfee found and removed it. But usually when this is the case I get notification that something was removed during a scan.

Any other ideas?

Thanks,

Mike

Try using Process Explorer instead of Task Manager to see which process is causing high CPU usage: Process Explorer