Although I'm considering replacing McAfee with AVG, I haven't yet made a final decision, and uninstalling the Security Center seems a bit extreme. I had my Windows Firewall turned off, and simply disabling McAfee through the Security Center didn't allow the free version of ZA install to continue.
ZoneAlarm has detected that you have McAfee Security Center installed. There are compatibility issues between ZoneAlarm and this product.
If you want to install ZoneAlarm, please uninstall McAfee Security Center and restart the ZoneAlarm installer.
Anyone have any ideas about how to resolve this apparent conflict? Frankly, I'm kind of shocked that there is a conflict, unless it's an attempt on the part of the ZA to promote their own AV product.