The user and password would be the one you used when you created the database.
However this is probably an issue with Datalinq being 32bit, or something in the Datalinq SQL template being wrong.
In my opinion, the easiest way to connect to databases like this in Datalinq is to use the Windows ODBC connection wizard, and then just connect Datalinq to the system DSN.
Use this windows program:
C:\Windows\SysWOW64\odbcad32.exe
And then add your SQL Sever to "System DSN":

You can use google to figure out any issues with connecting to your SQL database with the ODBC Data Source Administrator.
Ex. "How do I connect Windows ODBC to SQL"
Once you have your SQL server added to ODBC, you can connect to it in Datalinq like this:
