While Apple officially discontinued QuickTime for Windows and no longer issues patches, you can still find legacy installers for specific needs: QuickTime 7.1.6 Для Windows (RU) - Apple Support

Released in early 2007, QuickTime 7.1.6 was part of the QuickTime 7 family, which was a significant milestone for Apple. QuickTime 7 introduced H.264 support (high-definition video) and AAC audio, becoming the backbone of iTunes, the iPhone (which launched shortly after), and professional editing suites like Final Cut Pro.