Remove partition

Using a Windows 98 startup disk insert in floppy and start computer,select to run setup without cd rom support,at command prompt type in FDISK,in the window that opens select to delete extended or non dos partitions first (before deleting primary dos partition),press esc and proceed to delete the primary partition.
Proceed to repartition and formatting the hard drive using the startup,once this is complete you should be able to insert the Win XP disc and start a fresh install of XP.

Use your windows xp cd to boot pc delete all partions format ntfs or fat32 install & xp hope
this helps

If you can boot to the XP disk during the install procedure you will have the option to:

1-Delete all current partitions.
2-Create a single partition
3-Format the partition.

Buy the way format it ntfs.

Good Luck Lee