Hmm. Now its even worse. Decided to forget about any of the data on the drive, and simply delete all its partitions (from Knoppix), then re-install WinXP.
It doesnt work, keeps telling me "Error Loading Operating System"
Worse thought is that when I try and install Linux too, it refuses to boot, telling me that I do not have read/write permissions.
So, as far as I can see the only option is to go up to a friends house, get a copy of iolo Drive Scrubber (here)
, and boot the PC with that in the drive. Simply do a 7 pass complete drive wipe and start over with Windows again, and never touch Mandrake. Ever.