Super silent enrollment script Windows 8.1

Hi all.

Need help with the super silent enrolment script to install Symantec Encryption Desktop in Windows 8.1. What I nomally use for pre-8.1 Windows versions is the following:

msiexec /i C:\PGPDesktop.msi PGP_INSTALL_DISABLESSOENROLL=0

However this doesn't work anymore, the installation goes normally, as if there were no silent installation. Any experience on this?

Thanks.