INSTALL_PARSE_FAILED_INCONSISTENT_CERTIFICATES

         Failure [INSTALL_PARSE_FAILED_INCONSISTENT_CERTIFICATES] Error When         Trying To Install An App In Android 

  Failure [INSTALL_PARSE_FAILED_INCONSISTENT_CERTIFICATES]

This error occurs when you try to install an app via ADB and there is already another version of the same app which was installed from a different development machine.

To get round it uninstall the previous version and rerun the install.