It's a common problem when installing large hard drives with certain motherboards. I had the same problem with a 120GB a couple of years ago, it's just a case of informing the mobo that the drive is larger then it thinks it is.
As far as WinXP is concerned drives larger than 137GB do not exist.. but thsi can be remedied by installing support for 48-bit LBA (Logical Block Addressing).
Service Pack 1 is required for this fix, so i'll assume you have it as it's been out for a while.
A full explanation on how to enable 48-bit LBA can be found from the good people who messed this up in the first place 