Depends on your hardware rather than the operating system (although I think there may be a limit.. somewhere up in the Terrabytes though, nothing to worry about yet )
Most likely that if you have a system capable of running XP well then you have a system that will support >137GB.
However, check with your Motherboard manufacturer, or post what mobo you have and see if anyone knows of any limitations
OK, that answers my question.
I'm guessing that a majority of users here are using the older version of XP, well I am anyway.
I don't have a HD that big, and even if I do get one, I doubt I'll have a partition bigger than 120GB.
haha so what if i was to buy a new 300gb hdd and was just installing windows xp w/ service pack 1 would i have to partition it first before installing? i dont know exactly how to make more than one partition using fdisk i usualy do it through partition magic.