We never hope for a hardware failure. But we should always plan for one. But someday, it is possible that the server (or a critical component of the server) will fail. If you have wisely followed the counsel about Server Redundancy, you will have a backup server ready to use in case of an emergency. This will minimise your downtime.
What you need:
You may need to update the network drive connections for the server on each client computer if the IP address is different on the new server. Follow this guide How to Connect a Network Drive.