When running "PanUnInstaller.exe /qn" on a Windows machine to uninstall the GlobalProtect client, a popup window appears: "Are you sure you want to uninstall this product?"
This is because PanUnInstaller.exe doesn't have a "quiet" option.
This popup would prevent you from upgrading GlobalProtect client via Active Directory Group Policy Object (GPO).
Use the msiexec command to uninstall Global Protect client silently.
msiexec /uninstall GlobalProtect.msi /quiet
Using Active Directory GPO to Install the GlobalProtect Client