To install Opticon Inbox and all of its dependencies, have your device connected via ActiveSync to your PC, and then run MasterInstaller.exe on your PC.  The installer will utilize ActiveSync to deploy and install the necessary .cab files.  Please complete the install of each .cab file before clicking "OK" on the dialog box on the PC that prompts you to check your mobile device for any actions required on it.  This will mean answering all prompts and hitting the "OK" box in the upper right corner of the device's screen when each .cab file finishes installing.