i am using windows movie maker 2.6 because well it is all i clould find in a video editing program,. however i keep getting this message when i try to add a video to the movie maker.

The required codec was not downloaded automatically because the Download codecs automatically check box is not selected in the Options dialog box.

Which Code ?

What Download Codex check Box?

I have never seen this before. I am using Windows 10 64 bit HP. Was working fine until this morning.