System keeps rebooting after install of SecureClient

[Giel Habets]

When trying to install SecureClient NG AI R56 (fiile version 54.1.0.2, internal version 5) on a PC with XP Pro SP2 (Dutch language), one has to reboot to finish the install process. My PC keeps rebooting and cannot finish the install process.
However, when I start from a previous system restore point, use the CPClean utility to clean up any remains from the previous install, and again install SecureClient on my PC but now disconnected from the LAN and ADSL connection (both in a network bridge), then the PC reboots normally.
Before proceeding to the next step, the PC has to be connected again to the Internet (by allowing the LAN and ADSL connections).
The next step is to update the SecureClient configuration through authentication and the editing of the profile and press the "Update Now" button. Finishing the authentication and profile editing, and finally pressing this button results in an immediate shutdown of the PC that again keeps rebooting.

Any help or advice is welcome.

[Giel Habets]

I had an on-line chat with a person of Symantec Support, who informed me that Norton Internet Security does not support most (if any) tunnelling by VPNs.
That may cause the rebooting (I think). So, I can forget to use Norton Internet Security as long as Symantec does not redesign NIS.
This concludes the issue.