Microsoft Validation OS

Windows Validation OS (or WinVOS) is a minimal Windows 11-based environment intended to be used by Windows device manufacturers as an aid during early design stages. It is similar to Windows Preinstallation Environment in that it runs from a RAM disk and boots into a Command Prompt, although it is considerably more stripped down, leaving the bare essentials needed to bring up the Windows GUI and console. As a side effect of this, various user experience areas, such as the window caption buttons, do not fully render or behave as expected due to the components that have been removed.