I have been experiencing the same problem with Windows Movie Maker 2.6 operating in Windows 7 for months. It used to work fine in Windows 7, I installed 2.6 as soon as I realized the Windows Live version that came with Windows 7 had far less features. It worked well for about a year with the avi codecs I downloaded to view avi files.


One day in the middle of editing a video, the videos stopped displaying and I could only hear audio. I am unsure what happened. I can only assume when I tried to load a new avi file into WMM to use in my movie, it had a different codec that somehow effected the settings of WMM so no other avis could be viewed either. Every video file I loaded thereafter did not display, only the audio files. Windows Media PLayer continued to work as normal.

I am not sure how the settings changed to this day because I don't have the technical knowledge to investigate the conflict or how it happened. I tried deleting my codec packs and reinstalling. I tried uninstalling WMM and reinstalling.

Nothing worked.

I found this forum where somebody mentioned conflicts with the 64 bit operating system that I have in my system.

Still not sure why it worked for a year and then stopped working but.....

I located this 64-bit codec pack for reading avi files

I downloaded it and installed it and WMM is now working perfectly.

I thought I'd post in case this helps other people experiencing this common problem.