BleepingComputer.com: System background tasks

I have noticed that normally my system usage monitor is around 1-3% when idle (not opening/running any programs on my own). Using process explorer I have noticed that at times my system usage will jump to around 13% and stay at 13% eventhough I am not running any programs. Process Explorer does not show any specific file running but it does show that "system" is running. When this happens it will show that "system" is running for hours.

Sometimes I have to use a "hard shutdown" at this point to get the computer to shut down completely (it normally gets hung up on the part where it says computer is shutting down. Once it boots back up the system usage goes back to normal (1-3%) for a period of time (a few days or so) but then just out of the blue the system usage will go to 13% when I'm doing nothing.

I am running Windows Vista Home Premium 64 bit. I have run Norton, Malwarebytes, and Sophos Anti-rootkit but all of them come back "clean". Initially I thought it had something to do with my Roxio backup program because my event viewer log was showing consistent VSS errors, but this is just a guess. Any help is appreciated.

13% is nothing alarming. Sometimes, PE itself uses a good chunk of your CPU cycles.

Ok. Thank you very much for the reply. I get a bit nervous when my cpu usage spikes

You're very welcome