In the past, Microsoft would typically release a new operating system on several-year cycle. For example, Windows 2000 Professional was released in February 2000. Windows XP was released in October 2001, followed by Windows 7 in October 2009, Windows 8 in August 2012, and finally, the first edition of Windows 10 in July of 2015.

Notice there was an eight-year span from XP to 7 where no new desktop operating system was released. For many business and enterprise customers, desktop operating system updates were frequently tied to hardware refresh cycles. Compatibility testing, for example, could take months to complete. An operating system refresh also usually meant a significant amount of downtime for users. 

Here's an example of the deployment life cycle in a legacy management scenario whenever an operating system was released:

• First, requirements gathering. Administrators had to make sure the existing hardware was capable of running the new operating system and applications. If not, this meant budgeting for hardware upgrades, potentially adding months to an upgrade cycle.
• Once the hardware requirements were satisfied, the next step was configuring a system to be representative of what would be deployed to users. The configuration would then be captured as an image: a point-in-time snapshot of the operating system, drivers, updates, applications, and settings that would get deployed on subsequent machines.
• As time went on, the image would become stale. Administrators would then have to re-create the baseline image, updating the operating system, drivers, and applications, and then recapturing it.

This process would normally get repeated for every brand and type of device: a unique image for each model of desktop or laptop device. Fortunately, there's a new approach with Windows 10 Enterprise management.