Try using the VLC player - something in your Windows setup of QuickTime is awryPlease read the FAQ page for details
Q: When I try to play a video the sound is absolutely fine, but the screen just shows green/black fuzziness
A: Open QuickTime 7
Click on Edit tab and go to Preference,
Then click on QuickTime Preference.
Once that opens, click on Advanced tab
You will see a selection for video or Direct X : unclick the Direct X radio button
Click on Safe mode (GDI only)
Then click on Apply, then OK.
Restart QuickTime and play a movie to test.