What is the extension of the Access database file? If it is .MDB or .ACCDB then it would be connecting using ODBC, and the PC where it currently resides should have an ODBC connection defined. It is also possible to determine that connection by looking at the detailed properties of the SQL linked tables, but that might be a challenge for an Access novice.

The other possibility is that it has a .ADP extension, in which case it connects directly to the SQL Server database. Note that the latest version of Access do not support that format.