Windows XP SP3. Got frozen screen on reboot after installing ZA Pro 9, went to Safe Mode twice to uninstall.
Then I found that I could reboot OK if I first went to Safe Mode and unchecked ISW ("C:\Program Files\CheckPoint\ZAForceField\ForceField.exe" /icon="hidden") on Mike Lin's old but free and useful Startup Control Panel.
I still cannot reboot without getting a frozen screen if I check ISW to load it at startup. But I put ForceField.exe on my Start program list. It seems to work OK AFTER my Windows XP SP3 is all up and already running.