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[SSL VPN] NC error " Cannot start the Network Connect service. Please re-install Network Connect"

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Knowledge Base ID: KB20586
Last Updated: 11 Jul 2011
Version: 2.0

When launching Network Connect (NC) the installation process fails with the error  Use the following information to resolve the issue.

Problem or Goal:
For some users, when launching Network Connect the installation process fails and the following error is displayed: Cannot start the Network Connect service. Please re-install Network Connect.

This error appears if the Network Connect dsNcService component is not running.

Use the following steps to resolve the issue where applicable:
  1. Remove the following:
    • All Juniper Components (such as Juniper Setup Client, Juniper Network Connect, etc.) from Control Panel > Add/Remove Programs
    • JuniperSetupControl from Control Panel > Internet Options > General > Settings > View Objects
    • The Juniper Networks Folder from: 
      • C:\Documents and Settings\<username>\Application Data\
      • C:\Documents and Settings\All Users\Application Data\ 
      • C:\Program Files\
  2. Delete the following Network Connect registry keys from the Windows registry:
    HKEY_LOCAL_MACHINE\SOFTWARE\Juniper Networks\Network Connect<version number>

    HKEY_LOCAL_MACHINE\SOFTWARE\Juniper Networks\Network Connect\Debug\dsNcService

    HKEY_LOCAL_MACHINE\SOFTWARE\Juniper Networks\Network Connect

    HKEY_CURRENT_USER\Software\Juniper Networks\Network Connect<version number>

    For Windows Vista and Windows 7, also delete:




  3. 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)
  4. Restart the computer. Network Connect will launch successfully.

If the above did not resolve the issue:

Use the following steps on the clients computer:

  1. 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
  2. Double-click the service that did not start:  Network Connect service (dsNcService) 
  3. Click the Log On tab.
  4. Verify that the service has not been disabled for the hardware profile that you are using.  If it has, click Enable.
  5. 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.
  6. Re-establish Network Connect session.


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