MrWhiteUK, using a 98 boot disk to Fdisk and Format have always worked for me, and should always work for anyone... however, there is a way to do it through 2k, not using a 98 boot disk. If your BIOS allows you to boot from the CD rom, u can boot off the w2k installation cd and go into Repair Options, then Recovery Console (DOS). Alternatively, if you can't boot from a cd, you can make setup disks to boot from. However, if you can boot into 2k, which you can, open a command console, Start>Run>cmd. Insert the windows 2000 cd, go into the /i386 folder and type "winnt32/cmdcons" this will allow the recovery console to be a startup feature if you press F8 during the windows load.
Once in the recovery console, you have access to Fdisk and format. I've never removed 2k from a machine this way, but doing it through the recovery console should work.