Bad partition - this is easy. Options are
If the HDD had been partitioned with NTFS already - do this --->
1 - set BIOS to boot with the winxp CD, select to install windows, delete the partition, recreate it and continue on to format and install winxp
2 - OR set BIOS to start with win98 floppy, boot up and select CD Support, change to your winxp CD (drive), change to i386 - run winnt - go thru the winxp installation - deleting, recreating, formatting partitions, install windows
OR slave your hdd onto another winnt based machine and blow away the partion (never touch the small OEM on the hdd if this is an OEM machine)
If somehow it is FAT32 (highly unlikely as its OEM)
Just run fdisk and delete/recreate partions
Alternatively - OEM PCs come with Recovery CDs - you can try running this to reinstall winxp
Note - dont delete the OEM partion thats already on the Harddrive (small partition).
If you asked me - I had an OEM PC once - it had a winxp recovery CD - first thing I did - blow away the OEM partion - install winxp from my retail CD - get drivers and install other apps - all good. Last time I saw my recovery CD.
Let me know if you're still having problems - had worked for Microsoft Desktop for over 5 years this stuff is music to my ears. Theres more options than the above - post any messages you get and information like:
Brand of PC
Did it come with a recovery CD?
How big is the HDD
Win98 floppy ?
Errors yes errors important