It depends what updates are installed or slipstreamed with the installation as well as the file system used:
I beleive that XP can support partitions of up to 4TB when NTFS is used as the filesystem - but pre-SP1 installation disks wont be able create/format the partition during setup.
You'd have to create the largest it supports (137GB if I remember correctly), get into windows and then use something like partiiton magic to expand the partition to the correct size.
If FAT32s used, then I beleive the max size supported is 32GB. That may just be during the initial setup like with NTFs though.
Hope this answers ur question OK