[Breakdown]

Sorry, I posted initially on the wrong forum.
Simply I have upgraded my PC, now with Windows Vista, and added a Fire Wire Hard Drive. Previously I had used an XP based system and a USB driven external hard drive, anticipating problems until I upgraded.
My issue is that the sessions I have saved on the USB drive will not open properly on the new system. All the tracks are there, but no wav. data visible or audible.
What dumb thing am I missing, apart from the data that is......
I have simply dragged the session files from the old to the new.