Your CPU is overheating and good ole Intel is stopping the CPU from burning up.
Possibly the fan on the HSF [heatsink fan combo] that cools the CPU is dead or clogged with dust bunnies.
Take the cover off of the tower and clean out all the accumlated dust. It is in no way a sign of poor housekeeping, LOL, it is quite normal
I have a Systemax Intel Celeron 667Mhz with Windows ME 4.90.3000. Model # 003721684. There is a siren noise that sounds like a British Police Car coming from the processor. What is it trying to tell me? It comes on only when running any application except Internet Explorer. Not on with desktop. Processor turns off immediately once in awhile.

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