Once the PGP NetShare component has been removed via msiexec PGP_INSTALL_NETSHARE=0, it is not possible to re-enable this feature with the same version of PGP NetShare.
This is a known limitation with how the software currently works and is expected behavior.
In order to re-enable the PGP NetShare component, either Uninstall the PGP Netshare software, and then reinstall, or perform an upgrade to a newer version of PGP using the following msiexec switch:
msiexec /i PGPDesktop-newer-version.msi PGP_INSTALL_NETSHARE=1
As the above is a requirement, PGP Universal Server auto-updates to perform the install to the new version will not be possible.