when you partition it, you should have a drive "F" and drive "G". drive "F" is up to 137g and "G" is everything else. just go into evox or avalaunch or whatever you use and there should be an option in the settings to use drive "G". if i am wrong on any of this, sorry. i have only worked on my 120g but have read a lot about bigger hdd's. i believe your bios also has to support more than 137gigs, which should be most of the new ones i think.
the bios does have to support larger drives , I've read it can also be fussy with certain drives above 120gb, I'm in the same boat as Big_G-man I've only used 120gb so cant confirm for sure. Ta