Try removing all traces of Zone Alarm with this free appplication called Regcleaner.

http://www.vtoy.fi/jv16/programs/RegCleaner.exe

If that doesn't work, then try uninstalling Speed Disk or Norton Utilities or Systemworks (depending on what you have installed)and see if this will help the problem. Other than that, a Reinstall of your OS would be the next logical step.