Sir Bob, Ive had some troubles with Zone Alarm in the past but they havent been that bad. 1, You may have removed software from your pc in the last few days and this is what caused it not to work. Programs can 'share' windows files that are on your pc. 2, You got stung from a virus, viruses like to disable antivirus software and in some cases remove important files that are needed for the software to run.
Hope this helps