1) Download a Windows 98 bootdisk from here
2) Save it to your hard drive and then extract it to a blank floppy
3) After the boot disk has been created, download this file
and save it to your floppy
4) Boot your XP machine with this floppy, choose "without CD-ROM support"
5) At the prompt, tryp "FDISK" and then delete you partiton using this utility.
6) After you delete the partition, you'll have to create 1 primary DOS partition.
7) Exit out of fdisk and then reboot the computer......still boot using the disk, this time choosing "CD-ROM support"
8) type "format c: /s" and then "Y" at the confirmation and wait for your drive to be fully formatted.
9) Name the drive (if you want) and then from the A:\ prompt, type "smartdrv" and hit enter.
10) After smartdrv runs, switch to the drive letter of the CD-ROM drive containing the XP CD.
11) Once at the drive letter, type "cd i386" and hit enter
12) then type "winnt" and hit enter
13 It is going to ask where the location of the installation files are and it will have "E:\i386\" already populated (Where E = your CD-ROM drive letter
14) Just get rid of the i386 portion so you just have "E:\" and then hit enter.
15) This will start the install. Hopefully, you'll be able to take it from there? Remember to allow the XP install to format the partition using the NTFS format.
You should be good to go.