Getting computers on same Network drive

I have 5 computers on a Peer to Peer network but only the “server” and 1 other computer can access a particular program on a dedicated drive i.e. “D”

Computer 1 is
D on “Server”, mapped on F Drive and the D drive is a second Hard Disk.

Computer 2 is
D on “Server”, mapped on G drive and the D drive is the partition of the Hard Drive on C called Disk 1 part 02 on D.

Computer 3 is
D on “Server” mapped on Drive E and the D drive is the CD player.

Can anyone tell me how to get this particular program on the “server’s” drive “D” to be accessed by all the computers and how can I change the drive letters on the 3 computers not accessing the program to Drive “D” by re-mapping them to D.
Thanks.