Update: USB drive works fine, it's just sometimes the CD-Rom drive disappears completely from my computer (and device manager), and when this happens no removal storage works.
Pretty sure it's the BD drive and Win7....still can't sort it though
Managed to get to the UAC "run" question with vista tonight...but it doesn't go anywhere from there. The drive simply isn't working properly. I have an old CD-rw drive in a PC in the loft, pretty sure it's IDE but I might be able to dig it out to try running windows again? Just not sure such an old drive will work. Other than that the only thing I can think of is to go and buy an external drive in order to reinstall vista?