Unable to connect from remote computer, while local connection works I have a Windows 2008 R2 64-bit server with SQL server 2008 R2 installed on it.
I manage to log to SQL server with SSMS with the sa SQL account and with a test SQL account.
But when I try to connect from another computer on the same network I have the following error for both accounts:

Cannot connect to 192.168.x.x.
Login failed for user 'sa'. (Microsoft SQL Server, Error: 18456)

From the Event Viewer I have the following detailed errors

Login failed for user 'sa'.
Reason: Password did not match that for the login provided. [CLIENT: 192.168.x.y]
Login failed for user 'test'.
Reason: Could not find a login matching the name provided. [CLIENT: 192.168.x.y]

The error with the sa account implies I entered the wrong password, while I know I entered the good one.
The error with the test account implies the test account doesn't exist while it exists.
Remote connections are allowed on the SQL server.
Name pipes and TCP/IP are also enabled.
Rather than using the IP, Use yourdomain\SQLinstance

Also have you allowed the TCP port inbound through the windows firewall on the server side?

Also change server authentication:


Lastly I would change the Pass just incase