Do you have an Acer laptop? Is the CPU going full bore for no reason? Is your battery getting a bit old?
Then do I have a solution for you.
Fun problem at work this week, as above. The SYSTEM process – not the System Idle process, as you’d expect – was eating as much CPU time as it could, causing it to heat up and run its fans like crazy. Oh, and the laptop’s keyboard and touchpad were practically useless – it was ignoring 9 in every 10 keystrokes, and you’d get maybe 2-3 responses a second out of the touchpad.
I had to plug a USB keyboard and mouse into it; curiously they worked flawlessly. I guess it was too busy to listen to its PS/2 inputs.
I googled “system process using cpu“, and landed on an essay by Mark Russinovich (the Sysinternals guy) on how he used Process Explorer to hunt down whatever was using his CPU like crazy. His problem turned out to be bad network card drivers; in my case…
…it was something called Deferred Procedure Calls. A further google for that turns up a surprising number of Acer laptop users. This thread explains it all. There’s a hardware bug somewhere in the way certain Acers – at least the 1640Z, and some 3000 and 5000 series models – talk to old batteries. Possibly they’re getting hung up on it reading too close to zero, I don’t know.
The fix is simple. All you have to do is pull the battery out.
CPU usage will instantly decrease, and everything will return to normal until the next time you reboot with the battery slotted in.
If this is your problem, you have three simple options. First, you can chuck the battery out, leaving the laptop to rock from side to side on a flat surface because some of the feet are on the battery; two, you buy a new battery, gambling it’s the battery’s fault and not the laptop’s; and three, go buy yourself a shiny new laptop that isn’t crap.
Edit: I’m getting a lot of hits from people with recent Acer laptops, saying they have full CPU usage. This exact problem is to do with old batteries; if you’ve got a Core2 Acer or something similarly recent, it’s not the same problem and I can’t specifically help you. I suggest checking Task Manager (ctrl+alt+del, pick it from the list) and looking in the Processes tab – find what’s using your CPU, google the name of it and kill it. Aside from that I can’t really help.