This is truly
one of my biggest gripes about PT. (I have 3) If you check in your disk allocation window the system drive should be set to playback only. and the box with 'record using round robbin'
should not be checked. I don't know anyone who uses this feature, and if you should not ever record to your system drive, WHY IS THE OPTION EVEN THERE? If someone can explain to me why anyone would want to keep the audio files in a different location from the session, I'd like to hear it.
Make sure your setup is exactly as it was when you recorded your session. Go to the file dropdown and select 'record in' select a drive, and check the box, 'with audio files' just as spkguit suggested. If you haven't performed a defrag or move the files they should be located and moved with the others to it's new destination.
Good luck...