|What software is it? |
Does it talk to a database service (like SQL, Oracle), or is it just a flat file system database where all you need is a mapped drive letter (like MS Access or Excel spreadsheets)?
Can workstations see the server? Can they ping it?
Can the server see the workstations? Can you ping the workstations from the server?
Did the network address change? Example: Was it 192.168.1.x before and something different now?
Does the server have a static IP address? Is it possible something new on the network have the same address?
Is it a Windows domain? If so, are clients using the server as their DNS server?
Assume that I already did an Internet search.