I have 2 laptops running ZoneAlarm Free version 9.2.106.000. One laptop is a Dell Inspiron e1505 running Windows XP Media Center and the other is a Dell Latitude d630 running Windows XP Pro, both are fully updated to SP3. I was using ZoneAlarm Free and AVG Free Anti-virus on both laptops, but decided to switch over to Avast Free Anti-virus. I did a full uninstall of AVG on both computers, and installed Avast. On the Inspiron e1505 Avast installed fine and runs fine with ZoneAlarm. However, on the Latitude d630 when I installed Avast, ZoneAlarm stopped working. ZoneAlarm would not completely load. The icon would appear in the tray and when I hovered over it, it would say "Protection is Up, UI is initializing", and would stop there. If I tried to open Firefox or IE the computer would crash. Rebooting did not help, I had the same issue each time. When I removed ZoneAlarm the computer ran fine. When I reinstalled ZoneAlarm I had the same issue. When I uninstalled Avast the computer ran fine. When I reinstalled Avast I had the same issue. I tried wiping the HD and reinstalling Windows clean, but as soon as I installed ZoneAlarm and Avast I had the same issue. I uninstalled Avast and reinstalled AVG and the computer worked fine again.
After that long explanation, here is my question. Why will ZoneAlarm Free work fine with Avast on one computer, but will not work on another computer? Any suggestion would be very helpful. Thanks.