Finally got it licked, so to speak. Completely deleted the BD1 folder, did a clean MSTS and BD install on a works laptop (naughty, naughty
Then copied over the BD1 folder from the laptop to my main 'puter. Deleted the laptop install, can't let the IT stormtroopers from work have any excuse to bleat about unreasonable use!
Jobs a good 'un. Still can't work out why xcopy aint working though.
Many thanks for all your help.