WMP won't play AVI files

Hi,
I have several clients that can't play avi files. They receive the following
error:

"You've encountered error message C00D11B1 while using Windows Media Player.
The following information might help you troubleshoot the issue. "

I've tried on google, with a lot of possible solutions but no one seems to
be the right one.
What I've done: reinstalled Media Player 11, reset DRM, installed another
player such as VLC or DivX Player, and nothig happens! Every time I receive
the error above.

Any idea ?? The video files are not corrupted, I can play them on other PCs.
Also the sound card is working as well.

Thank you in advance

Regards,
Luca

The usual reason is that the codec required for the particular AVI file that
you are playing is not installed on the PC, but is installed on the others.
AVI files can be authored in a myriad of different codecs each of which
requires its corresponding codec to play it.