Laptop Processor Upgrade

[mother_russia]

I was on the Dell website looking at laptops. To upgrade to the Intel Pentium M Processor 770 (2.13Ghz) is an additional 500 dollars with some notebooks, but with the notebook I am looking at, it is not even availible. I have found this processor online for only 270 dollars online. How difficult would it be to buy the laptop with the lowest speed possible to save money, and then put in the new processor. Considering it's not availible with that notebook, does that mean it wouldn't be compatible? (I realize this would void my warranty as well)

 

[mother_russia]

Here's the XPS model that offers the upgrade:
http://configure.us.dell.com/dellstore/config.aspx?c=us&cs=19&l=en&oc=iXM140s1&s=dhs

Here's the processor specs:
http://www.dealtime.com/xPF-Intel_Pentium_M_770_2_13_GHz_processor_mobile

Here's the computer I want to put it in:
http://configure.us.dell.com/dellstore/config.aspx?c=us&cs=19&l=en&oc=i6000S1&s=dhs

 

[TheRecluse]

i don't know if it's possible.. it probably is, but i'm sure it will kill your battery life..

 

[dnoch]

I know that it is possible to replace the CPU on most laptops, but I think the choice on what CPU is very limited.
I would enquire with Dell first