Well the problem may be that other codec packs and/or codecs are conflicting with the CCCP in some way. The simplest way to do this is to use the CCCPI and a reinstallation.

Link to download CCCPI


So my advice here is the following

A correct (re)installation procedure goes like this:

1. Use the CCCPI to find any old codec packs (Matroska pack, K-Lite, Nimo etc.). If it says "previous installation" about something, that means you had the pack in question installed before, but that it is now uninstalled. DO NOT TOUCH THE "Register filter" AND "Unregister filter" BUTTONS!

2. Uninstall ALL codec packs that the CCCPI lists as "Installed", DivX, XviD, FFDShow (important!), VobSub and anything else codec-related you might have on your computer, including the CCCP if you had it installed before and playback still didn't work. Use Control Panel -> Add/Remove Programs to find and uninstall them properly.

3. Reboot. IMPORTANT.

4. Install the CCCP.

Tell me if this doesn't work