Chances are if you still have a dell inspiron 8200 its out of warranty anyway, so why not upgrade the processor for 15 dollars worth of parts? The pentum 4m series isnt hard to come by interms of scrap parts.

    [This project is available in a pdf for easy printing/ viewing]

Part	Site	Cost
New processor (pentium4 m, sl65cj) 1.8ghz	ebay/a friend/ a parts laptop	~$15
Torx screwdriver
Thermal compond

1: opening up.	here's the bottom of the laptop. yep, its a beast. 2 marked (phillips) screws go strait through to the keyboard.
2:	The procrssor's: im upgrading from 1.6 to 1.8 Ghz. note that both cpu's are rates at 35Watts, so there is no need to add in any extra thermal systems. also, they are from the same series and only differ in multiplier configuration.
3.	After removing the underside screws, the keyboard slides out (from the lcd side first). this reveals the mainboard innards as well as the processor and socket. in this photo i had allready removed the heatsink.
4: heatsink	The heatsink removes with 2 torx screws and slides out of the way.
5. Locking in the processor	The processor only fits in in one direction. mine came from a friend who literally put it in an envelope and mailed it, so i had to straiten some pins. make sure everything lines up
6.	Rebuild everyting and test everything out. remember to use thermal compound at the processor heatsink interface. Run cpu-z to see the difference