I use to do the full install so I think I just had to have CD1 in the tray... (and I have GOG copies, not free, but worth it so I didn't have to swap CDs if I ever went back to them.)
I learned the hard-way from Planescape: Torment 3-CD retail (had this BEFORE BG1, actually). First time, did the not-full install. Got tired of disc-switching. So annoyed w/ that - I uninstalled the damn thing & reinstalled with full install.
After that - ALWAYS full install.
- INMATEofARKHAM likes this