I have a dell inspiron 8100. I had a few issues with overheating and found this little program that lets you tweak the fan settings very nicely. No problems with overheating since. Also I upgraded to xp/pro and resolved a couple problems with some games I was playing. Might be worth a try.

edit: I just went and found the website with info on how to set this program up for dell computers. Here is the link.
http://www.diefer.de/i8kfan