Have you checked if the firewall is enabled? If so, the firewall may have block the connection to the DB. Please try to disable the firewall and perform the test again.
Besides that, the 3 MS jar files might be corrupted. Can you also try to replace the 3 files if disabling the firewall doesn’t work.
IN IS admin page | Settings | JDBC Pool, you can setup up your JDBC data direct connections to the relavant database such as DB2, oracle, SQL as well as embedded Database driver.
In addition to what others had suggested, if still didnt work, you may want to check from the SQL Server Configuration Manager if the TCP/IP is enabled.
If it is, kindly check if the TCP Port is set to the default value 1433 or what ever that port is you are using.