hi all sifus,

i just bought a 500gb sata western hard drive. i plugged it to my motherboard and ran it but my system could only detect it as 128gb.

my system
os: XP pro
Motherboard: http://www.asrock.com/mb/overview.asp?Model=P4i65G
ram : 2 x 512mb
hardisk 1 : 80gb hitachi ide
hardisk 2 : 500gb western sata(the new one)

is it because XP is too old to detect the 500gb or is it because of the motherboard? i went back to the shop and the technician could detect and opened up all 500gb for me but when i plugged it back my system could only say it is a RAW hard drive without any size. then i tried using xp to format but it would it say only 127~128 gb and not 500gb.
i tried using another tool partition magic 8.0 but it would only read the harddisk as 'bad'. dunno what that means but i could use the harddisk normally but limited to only 127gb.

help!