''Windows Presentation Foundation '' When the .NET Framework 3.5 is installed, the client computer is configured with a Windows Presentation Foundation plug-in for Firefox: http://msdn.microsoft.com/en-us/library/bb909867.aspx http://msdn.microsoft.com/en-us/library/aa663364.aspx if you have install Microsoft .NET Framework 3.0 or above do not disable it. ''Microsoft DRM'' read '''trolly''' reply: http://forums.mozillazine.org/viewtopic.php?t=418289 if you have Windows Media Player 9 and above do not disable it, maybe WMP crash ''your choice'' thank you Please mark "Solved" the answer that really solve the problem, to help others with a similar problem.

solved-thanks