i setup the server successfully with windows Pro 32 bit, as i fallow the guide from SambaPOS club, Server installation was successfully completed, also i started the client computer i installed windows 7 pro 32 same as previous one, i disabled firewall and the like and installed .NET framework plus sambaPOS then, i try to connect the remote database by goint to local settings. please look below shot.
So your SQL Express instance is SAMBAPOS3? What version of SQL Express?
EDIT Obviously it is since its connected on main terminal… So do you have TCP/IP enabled for the SQL Server also is SQL Server Browser service running? Did you check to make sure your SQL Server is accepting outside connections?