as a Microsoft operating system. Microsoft famously skipped the version number 9 and moved directly from Windows 8.1 to Windows 10.
There are official Microsoft products with "9" in their name that are often confused with an operating system: Download .NET 9.0 (Linux, macOS, and Windows) windows-9-free-download-full-version-softfiler
Various custom-built operating systems carry the "Windows 9" name but are actually modified versions of existing systems. as a Microsoft operating system