Hi there,
My CPU has been overheating for a while now. I have a Pentium 4 Prescott, 3.0GHZ with HyperThreading.
The idle temperature is 50 degrees, and when running at 100% it hits over 74.
It starts beeping repeatedly after 70, and I really want it to stop.
I have a rear fan, CPU fan & heat sink, and a piece that connects the CPU fan to the outside of the case. However it is making very little difference. Even when I open the case, there is no difference.
So I've been thinkin it's my power supply, however I am unsure how to read it, and what is adequate and what isn't.
I took a photo of my power supply and the information on it.
http://img.photobucket.com/albums/v33/Twitch222/PICT0061.jpg
Please help
Twitch

It is extremely unlikely your powersupply has anything to do with overheating. Overheating is a product of poor ventilation or poor thermal conductivity between the processor and heatsink. That's not to say you should'nt consider upgrading your powersupply as the one you have may be streatched on a P4 depending on what drives/fans and graphics card etc you have connected.

I suggest you remove the CPU heatsink, carefully clean off any old thermal pad or compound using isopropyl alcohol and apply fresh thermal compound. A small bead spread evenly over the CPU (Don't use your finger or any hard edged metalic object to do the spreading..Maybe a business card) and re-attach the heatsink.
Make sure you have cleaned out any dust/crud buildup from the heatsink before re-installing it.
I gather there is some kind of duct on the heatsink to either vent hot air or intake cool air to/from outside the case depending on which direction the fan is set.
You should also look at such things as using cable-ties to tidy up the interior of the case to improve airflow. An extra case-fan or two may be needed.
Although not recommended, there should be a setting in bios system health section to lift the thermal alarm point to a higher temp setting. Since intel pentium chips have their own thermal cutouts it should be safe to raise the bios alarm threshold.

I used to have a signature but it disappeared and I just couldn't be bothered writing another so please feel free to ingore this.

I dont see how it could be the powersupply making your CPU overheat although your current powersupply seems very weak.

If your cpu is overheating and your fans are all good the heatsink's contact with the CPU is probably no good. You probbably need to re-apply the thermal paste. Before you do that make sure the heatsink is clear of dust and see if that changes temps.

Oh and you may want to buy a good PSU.. I would go for a 400W or 450W Antec, or a similar good brand. Just make sure you buy a good quality power supply with 18A on the 12V rail, or at least 10A for dual 12V rail PSU's. Yours has just 8A which is very weak, my P1 systems all have 9 or 10A and they are 10 years old.

Mattwizz3 : )

Sempron 2600+ OC 2.2GHz
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nVIDIA FX5500 128Mb The Devil '64bit'
Damn Microsoft...
DIE STEAM DIE!

And check here:
http://www.jscustompcs.com/power_supply/

for a guide on PSU requirements for your system. Just tick the boxes for whatever devices you have and it'll tell you the minimum spec PSU you need. Of course wattage is not the only thing to consider. Look for something with dual 12V rails with at least 15 to 18 amps on each rail.

I used to have a signature but it disappeared and I just couldn't be bothered writing another so please feel free to ingore this.

Mattwizz3 and Richard59 are right about the thermal paste.

A new application will most likely solve your problem and it is very easy.

There are many types of paste but generic paste (Radio Shack) will work well.