Recently I tried the newest Zone Alarm Pro update which came out this month in hopes that it would finally work well with Windows 8 on my computer. It blocked nearly everything I wanted to do on my computer. I couldn't access the Control Panel or file folders nor could I access a lot of my programs even though I configured Zone Alarm to allow them. Furthermore it blocked several of my programs appearing in start up such as my nod32 antivirus (even though I configured Zone Alarm to allow it.).
What really made things worse was Zone Alarm blocked my every attempt to uninstall it from my computer even when I had Zone Alarm shut off. To fix things I finally had to restore my computer from an Acronis 2013 backup.
My current subscription of Zone Alarm Pro expires in mid May. Since Windows 8 has a decent built in firewall I definitely won't renew my subscription of Zone Alarm.