Latitude e6400 Throttling/Heating Issue

Can anyone give me a fix to this issue. My experience is the same as many on this forum and outside the forum. Over a period of time, my CPU goes to 100% use, even though there is no real application activity. I have been in touch with Dell about this issue and have had my motherboard and memory exchanged. When I spoke with the technician and then a manager after the motherboard was exchanged, they told me to reload my operating system and software to fix the issue, or they would provide no further support. I explained that this issue is related to the throttling issue and they told me they have no awareness of this issue and cannot help me.

Please help...what is the solution?

My small business has purchased many Dell computers and I really feel a lack of support on this issue.