When the new ZA is installed, registry entries for the old installation are still valid as they simply point to newer versions of the exact same files in the exact same pathways. This doesn't affect the computer or registry in any way. Thus, ALL old files have to be manually removed.
When a new version of ZA is applied, XP prevents old files from being replaced by new files because of certificate verification mismatches. Uninstalling Zone Alarm in the normal fashion does not remove all the files and folders. To clarify why this happens, the explanation is simple. It'll clean all traces of any old installation from your system, and you can now run a fresh installation with no problem.
Download and unzip the CMD file zfix.zip, then run it. ZoneLabs gives lengthy instructions on how to do that, but to make it easy, I wrote a simple command file.
Second, there's a mess of files and folders you must delete. First, if you were already using Zone Alarm, uninstall it. If you are having trouble updating or installing the Zone Alarm firewall, with error messages such as 'Validation failed for.' any number of dlls, or that it can't shut down the True Vector Monitor, etc., here is the solution. Trouble installing or updating Zone Alarm in XP: Several members here have used the uninstaller described in the text below successfully.
