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.
Windows Vista upgrade licenses pertaining to Windows Vista Starter through Home Premium was expressed by "Ars Technica"s Ken Fisher, who noted that the new requirement of having a prior operating system already installed was going to cause irritation for users who reinstall Windows on a regular basis. It has been revealed that an Upgrade copy of Windows Vista can be installed clean without first installing a previous version of Windows. On the first install, Windows will refuse to activate. The user must then reinstall that same copy of Vista. Vista will then activate on the reinstall, thus allowing a user to install