microsoft first announced windows store, a digital distribution service for windows at its presentation during the build developer conference on september 13, 2011. further details announced during the conference revealed that the store would be able to hold listings for both certified traditional windows apps, as well as what were called "metro-style apps" at the time: tightly-sandboxed software based on microsoft design guidelines that are constantly monitored for quality and compliance. for consumers, windows store is intended to be the only way to obtain metro-style apps. while announced alongside the "developer preview" release of windows 8, windows store itself did not become available until the "consumer preview", released in february 2012.