.Divx is just a fancy AVI file.
Anyhow there are two main methods of video playback
VFW: video for windows, an older method falling somewhat out of favour.
Directshow (part of directX), what all the cool kids are using these days instead, newer codecs and older programs do not agree with it.
Either open it with directshow, if you have avisynth installed the make a text document with the following line
directshowsource("videoname.divx")
you could also try installing a VFW version of XVID but I am unsure if the 4cc (DX50) is supported.
http://www.free-codecs.com/download/Koepi_XviD.htm