I haven't been able to install any updates since version 7.0483. I've tried everything in these forums for months, and still nothing worked! So today I tried something I just thought of, and it worked for me.
1 - Right click on the ZoneAlarm installation file.
2 - Choose extract files (I use winrar & it extracted the files to another directory)
3 - Go to the folder where you extracted the files
4 - Double click the file VC90RT.MSI and it will install VC 9.0 Runtime.
5 - Now try your original ZA Setup file again, and it should work! At least it did for me, finally!
Operating System:Windows XP Pro
Product Name:ZoneAlarm Extreme Security