Hi, thanks for the help, on here, it really pointed me in the right direction, and here's the solution.

I initially thought it was a problem with ntfs as partitioning the HD for fat32 and the other larger part to ntfs seemed to fix the problem with XP. It turned out that the issue was due to my old machine HP Vectra VEi8 and its bios not believing in HDD with capactities greater than 33.8Gig. Any HDD larger than this, and the machine refuses to boot once formatted.
The bios version is: HW.27.08, but you can download the latest version HW.27.10 from HP or simply this link:

HP Brio ba600*-* HP Brio BA600, System diskette flashable BIOS (Windows 2000 compliant) - HP Business Support Center

I believe the PC willl boot ok if a partition (any format - so I used ntfs which is required for win 2003 server) is less than 33.8Gig solely as a boot partition. the remaining disk space is still accessed ok once booted.

thanks again.