Thanks for the advice. I may have been a bit over-enthusiastic with the HS compound. Will research!
Room temperature is around 26 - 28, and the CPU is an Athlon 2600 Barton core running around 1730 Mhz.
In normal (1-5%) wordpro use, CPU temp is in the low to mid 70's. I have compared the reading from the CPU temperature utility to the BIOS and they are the same.
When I use any media format converter, utilization goes up to 100% and CPU temp reaches the low to mid 80's (at which stage the BIOS warning is going off all the time). That's why I use a CPU cooler program for now, until finances will allow a new case, motherboard, CPU, and 1 big hard drive.
You are right of course, the case is too crowded, but finances are a very limiting factor right now. It is a midi-tower with slots for 4 drives + 2 optical & has a case fan. I will post temp specs over the weekend as PC is at home.
Drives are IDE, mixed from 30 Gb to 160 Gb (accumulated over a few years).
From a purely technical point of view, I am interested to know whether one can shut down a HD manually, and also determine whether it is actually running or sleeping.
I have just located 3 solved questions on Experts Exchange that seem to indicate that you can both - but am not a paid member there (for now anyway - our currency is only 10 to the dollar!), so can't see the answers yet. If anyone wants the links I'll post them.