My cpu temperature never changes from 80C

There is a temperature software appl for the Dell Latitude that you might consider, which monitors temperatures, fan speeds.
The URL for it is: http://www.diefer.de/i8kfan/

You can review the manual on their website to see if it might work for you.
You can monitor temperatures, control fan speeds, or both.

It does say that Dell does not support the app, so you couldn't get dell support if there were a problem.
Nice info there, and if nothing else, you could learn more about temperature monitoring

I agree with the previous reply about the "stuck" temperature gauge is not working properly.
There is a thermal probe in the CPU, and usually several on a motherboard so you can measure temperatures, say near the Chip set, near the RAM, etc. The temperature control apps can automatically change the fan speeds depending on the temperature, or let you do it manually.

If you get a "fixed" readout by one app, but varying temperatures using another, then the first app is not functioning, The thermal probe has to be working and changing resistance to give you the varying readout you are gitting with the HW-Monitor app.

Another similar app highly recommended by MaxPC is SpeedFan, which measures temperatures, and can adjust fans accordingly.