I have NOD32, ZoneAlarm Pro and free Process Guard protecting the "True Vector Engine". Ever since I installed Process Guard (last one to install), there were cases when I opened a new application, e.g. MS Word, the taskbar was frozen while the rest of the system was still responding. On one occasion, I could open the task manager by using Ctrl+Alt+Del and did a restart. One the other occasion, I had no choice but power off to shutdown. Is this related to PG or PG conflicting with ZoneAlarm? I did enable all the "General Protection Options" and Program Checksum Protection.
I am running latest version of Zonealarm Pro, and full version of Process Guard 2.0. No conflicts with them on my system. Don't run Nod32 however. I also have all the protections turned on.