Windows XP allows the creation of both standard and administrative users. When logged in as a standard user, to some extent your computer is protected machine wide modifications, some of which may be harmful.
However most Windows XP users always log in as an administrator and so the advantages of running as a standard user are lost.
Windows Vista runs applications by default as a standard process, even when the user is logged in as an administrator. If an application or control panel requires administrative privileges the user has to explicitly allow it. Thus the computer is more protected against harmful machine wide changes.
Software has to be modified so that when it runs on Windows Vista it does so as a good citizen and does so explicitly rather than taking advantage of Vista's backwards compatibility. To this end, a manifest has to be added. This manifest tells Vista that the application is aware of the change in policy and also what security level it should be run at.
DiffEngineX could already run as a standard process and so the changes it needed to run on Vista were minimal. DiffEngineX was submitted to VeriTest for testing and was awarded the Microsoft Certified for Windows Vista logo.
Application List: Certified for Windows Vista
In order to gain the logo, DiffEngineX had to pass many tests. One of which is that its uninstaller has to contain a dialog box that informs the user that DiffEngineX cannot be uninstalled if it is currently being used! Unfortunately Visual Studio 2005 Professional does not add this dialog box by default. The information on how to add this dialog box was generously provided on one Microsoft employee blog.