My client's laptop has been overheating a lot.
She says when she has it on her lap it burns her leg, when she has it on a table, it gets very hot as well.
Disk tests and memory tests are fine, and the Event Log says there's nothing out of the ordinary.
Because it's a Dell Inspiron 1200, lots of CPU performance monitors don't work with it, so I downloaded the one specific to Dell.
The CPU temperature is 60C, the disk temperature is 38C. With that software, I can force the fans to run at double speed, but then that hampers performance.
She only uses it with the power supply plugged it.

Systems specs:

Windows XP SP3
768MB RAM
40GB HD
Dell 0FD381 motherboard
Dell A05 21/6/05 BIOS
Intel 915GM Chipset

She says when she has it on her lap it burns her leg

That's one reason there is a push away from the term "laptop" and on towards notebook. Notebooks should ALWAYS be operated on a flat hard surface to allow for air flow underneath.

Notebooks, like all computers that use fans to draw in cool air, must be cleaned of heat trapping dust and dirt periodically. Unfortunately, notebook makers do not provide an easy way to do that for the typical user, and it should be left to someone more comfortable disassembling notebooks. Still, all the removable devices and access covers can be removed to allow access with a can of compressed dusting gas, or a properly setup air compressor.

Note too that weak batteries tend to strain the notebooks charging circuits causing both the battery and the charging circuits to work harder, thereby creating more heat. It may be time to start budgeting for a new battery.

Finally, I recommend a Notebook Cooling Pad w/ext. power supply. I like the external supplies because they don't draw power from the notebook - which only creates more heat.

Wow, I've never seen a processor get that toasty. Have you cracked it open to make sure there isn't a thick layer of dust on the mainboard? Also, if she has the battery in while it plugged in and it's fully charged...it does more harm than good.

Wow, I've never seen a processor get that toasty. Have you cracked it open to make sure there isn't a thick layer of dust on the mainboard?

As I mentioned above, opening a notebook case is not normally a user task.