Windows 10 is a
personal computer operating system released by
Microsoft as part of the
Windows NT family of operating systems. It was officially unveiled in September 2014 following a brief demo at
Build 2014. The first version of the operating system entered a public beta testing process in October 2014, leading up to its consumer release on July 29, 2015, and its release to volume licensing on August 1, 2015. To encourage the adoption of Windows10, Microsoft announced that during its first year of availability, upgrades to the operating system would be made available free of charge to users of
genuine copies of eligible editions of
Windows 7, and
Windows 8 after update to
Windows 8.1.