"We have our data (tables) in a separate database that is linked to the program installed on several computers throughout the Company. Both the data file & the program file are on our department's server. Everything works fine as long as one user is using it at a time. If a second tries to get on at the same time, it says the data file is already in use and halts. Does anyone have an idea of what could be wrong?"
Look at the network permissions for the folder that holds the BE. For multi-user access to Access, every user
needs create, rename and delete permissions; some network admins don't grant these.
When the first user opens the mdb, Access tries to create an ldb file for record locking. If the user doesn't have create permission, Access can't create the ldb & nobody else can get in.
When the last user closes the mdb, Access (95 and up) tries to delete the ldb. If it can't, you'll see it remain and think that somebody crashed something.
Also, you can't compact the database without these permissions.