I would suggest running the intel utility at:

http://www.intel.com/support/process...tools_proc_id&

as soon as you get whatever you buy out of the box. Out of less than 10 purchases over the last several years, I have had 2 substantially underclocked new laptops. The manufacturer had no problem replacing them, but I only knew it because I specifically tested the boxes ... you can very easily pay for a 2.4 GHz box, recieve a 1.7 GHz and never know it.