Can't access the software for DS50 digidtal recorder

Hi there, i ve just bought a DS 50 and the software version 7. 3 won' t install even though when i try to use the CD. When I retry, it says that it's already installed but it isn't and I can't access the DSplayer to save my recordings. I've contacted the helpdesk and they've sent me the update for version 7.3. but this is no good as there is nothing there to update, so I've asked them to send me the full version to see if I can install that. I'm using windows vista, so might this be the problem or is anyone else having this problem. It's all very well having the DS recorder but if you can't save files to your PC it's a bit useless.