Try installing FFDShow (it is a DirectShow filter which decodes DivX 3.11, DivX 4.xx and up to DivX 5.xx):
Windows version - http://athos.leffe.dnsalias.com/ffdshow-20040718.exe 
i can only find message boards and a few sights but i cant find where to dl the damn thing, i just wanna watch red vs blue and its pissing me off! plz email me the adress i beg u!