I have a Dell E520 in which I've fitted a Q6700 2.66ghz CPU with stock cooling.
In XP it ran at about 35 degrees, 45 or so when under load. Since upgrading to Windows 7 (64 bit), the normal temperature is around 42 degrees, BUT, CPUID hardware monitor has recorded peaks of 66 degrees or so (somehow, whenever I turn my back).
Are these temperatures OK? I'm planning on fitting a WD Caviar Black HD into the unit which apparantly runs hot, and I'm scared of adding more temperature to the CPU.
Read the Temperature guide at the top of the overclocking section. There are too many variables to say for sure your temps are a problem, based on the info you provided. Give that a good read then come back with your results.