My apologies, I didn't read your second post very well. I am quite sure that Win XP does not have a partitioning feature, as I remember ( 6 years ago?!) asking my computer genius friend what to do and was given a copy of Partition Magic for my Win XP machine.
If you do have issues ( you probably won't ) you could still (!!):
If it doesn't want to work, you could always take it out and install it in an external enclosure and do the partitioning on someone elses larger Win 7 or 8 desktop. It won't make a difference as long as you make sure to use the same file format, Fat 32 or NTSF for your system. The software will allow you to use a different format than the native format from the main system compared to the disc you are partitioning. NTSF- Native, and fat32 for Win XP. Double check which format you have and don't change it even though you could!