The Test Mode watermark in Windows appears if you install digitally unsigned drivers. Learn how to remove the Test Mode watermark.

Learn how to turn on or off Developer Mode in Windows 11/10 using Settings, GPEDIT & REGEDIT. You don't require a Developer License to develop!

Microsoft removed the ability to boot to DOS in order to speed the start-up of Windows Me and to eliminate the support hassles caused by real-mode device drivers that load before Windows.