I am sorry that you are having trouble with Express. This error indicates that one or more of the Express installer files have been removed from your computer. This can sometimes happen when upgrading Windows or they may have been removed in error. To resolve this issue, you will need to fully uninstall Garmin Express using a Microsoft Fixit application and then reinstall Garmin Express from http://www.garmin.com/express.
To uninstall Express, follow the instructions here:
What should I do if the computer cannot find the .msi file when updating a Garmin Software Application?
If you have any trouble with this process, or are still having issues after completing it, please contact Product Support by phone.