You could try making yourself a bootable slipstreamed XP/SP2 cd from those XP setup files if thats what they are.There will be a WINNT.EXE & WINNT32.EXE in there along with 5 or 6 thousand other files if it is the right ones.
Thats the best way if you can manage it i think,theres loads of howtos out there.Just google "slipsreamed XP/SP2 cd`s"
You can also copy the i386 directory to a cd normally and with the help of a 98 bootdisk(or similar) reformat the drive,copy the i386 directory onto your newly created partition and run the WINNT.EXE from there.
Thats how i ended up doing things on our very first pc last year anyway.I was actually a complete pc noob at the time so i barely knew the differnece between a DLL & a LOL and just had to learn as i went.

It was also the used XP from a friend though and of course it was in a right old state(hence the reason she bought new probably)
By time i eventually managed to re-install the thing though it was already too late......my attentions were elsewhere