I spent a couple hours fighting this upgrade. The zapSetup_70_462_000_en.exe would not work, it kept giving me this:
zlclient.exe
The application failed to initialize properly (0xc0000142). Click on OK to terminate the application.
It did not matter, clean install or Upgrade. So I went back to zapSetup_70_362_000_en.exe (that worked), and then I found out on here that zapSetup_70_408_000_en.exe was available, and that works.

Operating System:Windows XP Home Edition
Software Version:7.0
Product Name:ZoneAlarm Pro