Hi

I no longer can hear .mp4s when using Movie Maker.  Video is fine.  These files have been taken from my Canon Camcorder.  They play fine with Windows Media Player and with Adobe Premiere Elements (not a big fan of this program however).

Another interesting quirk - if I try to play a .mp4 through Movie Maker, it cuts the audio completely - so following this even .mov files no longer have audio on any program until I reboot the computer.  Then all files play fine - except the .mp4s still are missing sound.

I tried the Microsoft Fix It Tool, however I get the following message.  "We're sorry, but your operating system is not supported by Microsoft Fix it at this time."  I am running Windows 8.1, so I am very surprised to see that Windows 8.1 is not supported. 

I ran Media Info and got an annoying little Malware with it.  Media info mentioned Quicktime, so I uninstalled and reinstalled Quicktime and Movie Maker twice each, but there was no change.

Can you please help?