Today I was notified by my ZA software that a "critical" update was ready to install. After installation and the required reboot, none of my applications would start. It didn't matter if it was from the Start menu or a shortcut. Interestingly, my Norton Virus software was also disabled. I couldn't even open the Help menu from Start, to go back to a prior restoration point. My only option was to reboot, start in SAFE mode, and then completely uninstall Zone Alarm from my computer. Upon rebooting and starting in normal mode, my system worked fine. No problems.
Let's just say that ZA has lost a customer. If anyone else has this issue, simply do as I did above, and you'll get back to where you can use your system again. What is frustrating is I have been a faithful ZA customer for over 5 years, with only minor problems to date.

Operating System:Windows XP Home Edition
Software Version:7.0
Product Name:ZoneAlarm Pro