Suppose I have created an Add-In that needs certain requirements met before it can be used. (e.g. say it needs to be run in Excel 2007 or higher or say it needs access to the VBA Project Object Model)

When the end user goes to install this add-in, I want the following to happen:
  1. Check what requirements have been set for this workbook
  2. Check if the users environment meets all requirements set
  3. If fail any of the above requirements, alert the end user by means of a message box
  4. Unload the Add-In (i.e. the AddIns manager shows it unticked)

Would anybody be able to assist with this project?

So far I have achieved points 1-3 (although I think it may be firing by WB open event not WB install)