Ali·
Those of you who own an official copy of Windows 7 from MSDN or TechNet may have faced a scenario where you wanted to install a different edition of Windows, only to find out that you will have to download a separate ISO file just to install your desired edition. Windows Vista had one ISO file installer for all the different edition of Windows. But with Windows 7, Microsoft changed this approach and started offering separate ISO files for each edition (Starter, Home Premium, Professional and Ultimate) of Windows. This creates an unnecessary strain on bandwidth when downloading, wastes space when archiving, and wastes time in general.