Periodic kernel activity on Windows XP x64

Question

I've got a Windows XP Pro x64 maching, running on Intel Core 2 Duo, 4GB ram, all latest updates installed. A week ago or so i've started noticing high CPU usage. Looking at the task manager i see the System process periodically using up to 42% of CPU (kernel time, with a period or approx 10 seconds). It does it all the time. Restarting does not help.

Any ideas?

Answer 1

Almost certainly drivers, possibly a bad one came through Windows Update.

(And yes, Super User)