If Quark 6/7 won't launch and reports it needs to be reinstalled, try this first:
1. Delete the /Library/Preferences/Quark folder.
2. Run the following installer: /Applications/QuarkXPress 6.1/For System/QuarkXPress Component
3. Relaunch Quark and reactivate when the dialog appears
4. Test saving, relaunching, etc.
If that still doesn't work, the application should be reinstalled using the disc that you purchased.
