Yes, thats is what i mean.

AVI files can all be different. Its just a container for audio and video streams. E.g one can use the MP4 format (with say, the XviD codec) for the video, and MP3 for the audio whereas another AVI file (which to an average joe user,looks and acts prettymuch the same) could use the H.264 format for the video and AAC for the audio. One may play on one piece of hardware, another may not, leaving the user confused just like you are.

You need to go and find out precicely what codecs and formats your picture frame supports, and then convert it to that.

its avi.
im sure.
but i have no clue about the codecs.
it supports avi. but i dont knwo wat codecs

if so, is there anywhere online where i can find excatly what codes and formats?

Whats the make and model of the frame? do you know that?