Microsoft described Windows 10 as an "operating system as a service" that would receive ongoing updates to its features and functionality, augmented with the ability for enterprise environments to receive non-critical updates at a slower pace, or use long-term support milestones that will only receive critical updates, such as security patches, over their five-year lifespan of mainstream support. Terry Myerson, executive vice president of Microsoft's Windows and Devices Group, argued that the goal of this model was to reduce fragmentation across the Windows platform, as Microsoft aimed to have Windows 10 installed on at least one billion devices in the two to three years following its release