If you have XP on NTFS then it wont be deleted thru Dos.....d/l
Bootit NG..and create a Bootable Floppy from it .....Bootit NG can Delete any Type of Partitons..
BootIt NG Features:
Compatible with all Windows versions including XP/2003.
IEEE1394/USB 2.0 high-speed support for imaging/partitioning
Support for large hard drives (2 TB) and partitions (1-2 TB)
Non-destructive resizing and conversion for FAT/FAT32
Non-destructive resizing for NTFS
Creation and (secure) deletion of partitions/volumes
Undelete partitions/volumes
FAT/FAT32 formatting
Copying and moving of partitions/volumes
Support for Linux Ext2/Ext3 and ReiserFS file systems
Imaging (including directly to CD-R/RW or DVD+R+RW-R-RW)
Booting any partition on any hard drive (via BIOS)
Booting from the CD/DVD drive
Booting multiple operating systems from a single partition
Create over 200 primary partitions (if desired)
User ID and password protection
Free upgrades (1.00-1.99) (registration-key versions only)
And lots more...
Method : after you have booted from the Floppy..it will welcome u with mgs that welcome to installation etc.....clacel it..and go to partition works....now u can play with your partitions