I was having trouble with updates - consuming 70-80% of system resources, taking hours (literally), happening multiple times a day. I see from a number of other threads that this is not an isolated problem. I would post this in one of those threads, but they appear to all be locked.
I contacted tech support about this and they suggested resetting ZoneAlarm:
* Hold down Ctrl and Shift, then while holding them down right-click the ZA icon in the system tray (next to the clock in the lower right corner of the screen).
* Choose "Reset" from the box that comes up. (Note that this option does not appear unless you held down Ctrl and Shift while right-clicking.)
* Choose Yes on the Reset Settings dialog box.
* When prompted, restart the system.
* Follow on-screen prompts after restart.
This does remove all your settings. So a little annoying. But, after doing the reset, updating only took a few minutes and only consumed ~20-30% of cpu cycles. Huge improvement. Computer is usable again. So if you are having this problem, I suggest trying it.
Tech support also suggested that if the problem continued, I should:
* Open ZoneAlarm, click on Antivirus/Antispyware
* Click on Advanced Options
* Click on Updates
* Change updates to only occur once every 24 hours
* Click on On-Access Scanning
* Turn it off or set it to Smart Mode
* Click OK to close the window
* Disable debugging in ZoneAlarm by holding Ctrl and Shift while right-clicking the ZA icon in system tray, choose "Set debug level", and set it to Off.
I can't comment on whether these steps would have helped further (didn't try them), but perhaps they will be useful to others.