DVR-MS component introduced in Windows XP Service Pack 1. The DVR feature of Windows XP Media Center Edition, Windows Vista and the Windows 7 version of Windows Media Center create files in this format. If a recorded broadcast is marked as copy protected, the resultant DVR-MS file can only be played back on the recording device. Unprotected DVR-MS files (files not marked in this way) can be played back on any device running Windows XP with Service Pack 1 or later Windows operating systems, hotfix 810243 for Windows XP RTM (which adds DVR-MS support to DirectShow), and on Windows Mobile 6.
Operating system systems that have fixed deadlines use a real-time operating system such as VxWorks, PikeOS, eCos, QNX, MontaVista Linux and RTLinux. Windows CE is a real-time operating system that shares similar APIs to desktop Windows but shares none of desktop Windows' codebase. Symbian OS also has an RTOS kernel (EKA2) starting with version 8.0b. Some embedded systems use operating systems such as Palm OS, BSD, and Linux, although such operating systems do not support real-time computing. Operating system development is one of the most complicated activities in which a computing hobbyist may engage. A hobby operating system may be classified as