Your gonna have to have a partion before you can install XP.

Use a bootable floppy for your computer. If you don't have one to www.bootdisk.com . Turn off your computer-->put the floppy in the A: drive--> Power on the computer. then what you want to do is get to the command prompt. Type fdisk. It should then bring you to a screen asking you if you want to enable large disk support. Select yes. You will then have several options.

1.Create a new partition
2.Create a logical dos drive in the extended partition.
3.Delete a partition.
4.View partition information.

It will be something similiar to that. What you want to do is delete a dos partition. So select a number that corresponds to that. Then select the drive and delete it. I believe that you have to restart your computer then. Keep the A: disk in the drive and reboot. Get back to Fdisk again, but this time you want ot create a new partition. Select the number corresponding to that. Since your not to experienced with this I would suggest using all available disk space. It will then do a couple things.

Next, reboot the computer with floppy still in the drive. However do not go to Fdisk this time. Instead when you get to a command prompt which should look something like this c:> type format c:
then select yes.

After Hard Disk is formatted install you Windows XP.

Hope I helped you.