Registered: Sep 2008
07-13-12 12:43 AM
Without concrete evidence, it is anybody's speculations. Have your Task Manager Ready. When the CPU usage spikes up every 30 minutes as you said, you should be able to ID what process (and thus an image name) that is taking up most of the CPU cycles at that moment. You start from there.
For all we know... it could be an antivirus scan. Maybe something comes with your box by the vendor.
Or Google waking up every 30 minutes and sends reports of all the websites you have visited and all your keystrokes.