the easiest way to check that is to:
1) install latest divx -
www.divx.com
2) install latest xvid -
www.koepi.org
3) go to ffdshow preferences and in "codecs" tab, for "xvid", "divx 3", "divx 4" and "divx 5" formats set "decoder" to "disabled".
You can always change it back.