I buyed and installed succesfull this WD2500BEVE in my XT6200.
The correct algorithm is:
1. download the Data LifeGuard Tools at http://support.wdc.com/product/download.asp?groupid=701&lang=en
2. create boot floppy and create the partitions (no more than 137Gb every) in LifeGuard Tools
3. install Windows XP (with SP2! – very important). If you’ll install the Windows XP from recovery CDs (for laptop) then only 137Gb will be available because SP2 is not included there.
BIOSĀ in XT6200 will display 137Gb anyway but Windows XP SP2 will work correctly with all 250Gb
PS: I tried to install the Vista but for some reason the setup is hang. Not sure why – maybe DVD corrupted. Anyway now I work with Windows XP SP2 without any problem.