Where can I get the 3ivx codec ?

[W-Side]

I once installed this one "3ivx_d4_451_win.exe" now it says it only worked for 30 days even though the page said it's freeware

on another page I downloaded this one "3ivx_d4_451_os9.sit" but I dunno what to do with it since it's not .exe

does anyone know where I can get a setup file that'll keep working or how to use the ".sit" file I got ?

thanks