Having the same problem here!
cpu: HP compaq 8510w
Windows 7 Professional x32
Intel(C) Core(TM)2 Duo processor (2,50 GHz)
When I don't charge my Laptop it works fine, but as soon as I plug in my recharger the CPU usage shoots up to 100%. When I run the task manager and resource monitor it gives the following percentages:
perfmon.exe 31% (the resource monitor)
taskmgr.exe 29% (the task manager)
the rest of the processes vary from 0-5%, all normal I guess.
When I unplug my Laptop the CPU usage returns to normal and my computer works just fine. I'm starting to think it's a Windows 7 problem, but I hope someone can help me with this.