hello.
An error message occurred while establishing a connection to SQL Server: Server not found or unavailable.
Server not found or unavailable
Re: Server not found or unavailable
According to the error message, probably, the remote server is unavailable or remote access is forbidden to it.
Most likely the connection to the server is blocked by some antivirus software or firewall.
You can use the documentation to configure a remote connection to the server:
blogs.msdn.microsoft.com/walzenbach/2010/04/14/how-to-enable-remote-connections-in-sql-server-2008/
support.microsoft.com/en-us/help/968872/how-to-open-the-firewall-port-for-sql-server-on-windows-server-2008#LetMeFixItMyselfAlways
Most likely the connection to the server is blocked by some antivirus software or firewall.
You can use the documentation to configure a remote connection to the server:
blogs.msdn.microsoft.com/walzenbach/2010/04/14/how-to-enable-remote-connections-in-sql-server-2008/
support.microsoft.com/en-us/help/968872/how-to-open-the-firewall-port-for-sql-server-on-windows-server-2008#LetMeFixItMyselfAlways