We usually like to use this utility called Nir Soft Installed Codec.You can download Nir Soft's Installed Codec from here.However sometimes files are corrupted or deleted which would break Direct X.
The easiest way to check to ensure Direct X is working is to run dxdiag.
This program can be found on all installations of Windows Vista and Windows 7.
Desk Scapes has been fully tested with the Microsoft MPEG-2 Video Decoder.
In order to determine if you have a proper video codec utilizing a third party utility usually works best.
Once you decide which codec(s) are giving you problems you should remove the culprit by disabling or uninstall the program that it installed with and if necessary find a replacement codec that does the same thing, but is compatible with Desk Scapes.