Windows Media Player 11 – WUDFSVC.DLL
Wudfsvc.dll is a "user-mode driver framework service". It installs with Windows Media Player 11.x. The file will appear in your Windows\System or System32 folder. The wudfsvc.dll file is a library that contains the driver manager. Wudfhost.exe is the executable file for the driver host process. Wudfpf.dll is a library that contains run-time support for the framework, and wudfx.dll is a library that contains the framework itself.
Unless these files are causing you problems, we'd recommend leaving them in place. They don't necessarily need to be running all the time but they will be running when Windows Media Player is running. More information can be found at http://www.microsoft.com/windows/windowsmedia/player/download/download.aspx.
Safe
Microsoft