Officially unveiled in September 2014, Windows 10 is the latest of Microsoft’s desktop operating systems based off the Windows NT lineage. It is available in two primary versions — Windows 10 Home and Windows 10 Pro.
Windows 10 introduces universal apps that can be ran on a variety of devices like laptops, phones, and tablets. You can purchase an activation key for the Home version for $99. Microsoft is also providing its Windows Insider Program, which provides activation keys for those agreeing to test the latest OS updates.