Apologies ahead of time if I have the wrong forum--this isn't exactly a cooling issue, but I dont' know where else to put questions about throttling. I've got a socket 478 P4 2.4Ghz that is throttling like mad and locking up, both in and outside of Windows. But according to the temperature gauges, it isn't even close to overheating (it reaches about 40C, at most, before throttling kicks in). I'm not entirely sure under what _other_ conditions a CPU may throttle, but am I right in my understanding that throttling can occur due to internal errors as well as thermal issues? Should I be worried that the P4 CPU is failing? I've temporarily replaced it with a Celeron CPU (which I keep handy for testing), which seems to run just fine; but obviously as it's a significantly weaker processor, it isn't stressing the system as much or creating as much heat. I've run tests on the hard drive, RAM and mobo running under the Celeron, and everything checks out. Suggestions appreciated, and apologies again if I should have posted this elsewhere (if so, please tell me where I should have posted it) Thanks!