The database is a single file that needs to be stored on a computer in which all client computers have read/write access to. On this host computer, create a folder and create a share for that folder so any client computers on the network can access the data in the folder. The exact details of sharing a folder varies depending on the version of Windows but the basic way is to right-click the folder, select Properties, select Sharing, and then turn on file sharing. Make sure the sharing permissions give users read/write permission to the folder. You can also assign a share name which will be the name that all the other computers on the network will refer to the folder by.

To create the database inside this folder requires a client be installed. Preferably, on the computer that is used by the person who is going to administer the OpsCenter system.  The OpsCenter client software does not need to be installed on the computer that is hosting the database file.  Once a database location has been decided on, go on and install the client setup program.