Check that the latest version of Java is installed on the client machine (this is a must.). Also check whether the Java installed on the client machine is enabled or disabled. If Java is disabled, then enable it.
(Note: If Java is disabled for a long time, it is recommended to uninstall the existing version of Java and install a latest version of Java on the client machine)
Restart the computer. Network Connect will launch successfully.
If the above did not resolve the issue:
Use the following steps on the clients computer:
For Windows 7 and Vista systems, go to Start > Programs > Administrative Tools > Services. For older Windows systems, go to Start > Control Panel > Administrative Tools > Services
Double-click the service that did not start: Network Connect service (dsNcService)
Click the Log On tab.
Verify that the service has not been disabled for the hardware profile that you are using. If it has, click Enable.
Click the General tab. Verify that the service has not been disabled in the Startup Type box. If it has, click Automatic to have it start when you start the computer.