Core issue
The Microsoft Windows Installer (MSI) for the VPN Client installation now allows the VPN Client to be upgraded without the need to reboot under these circumstances:
Resolution
In order to suppress the reboot, issue the msiexec /qn /i vpnclient_setup.msi REBOOT=ReallySuppress command.
Refer to the Rebootless Client Upgrade for MSI Installer Only section of the Release Notes for Cisco VPN Client, Release 4.8 for more information.