Details:
After taking steps detailed in the wiki:
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2. Download CCCP Insurgent (CCCPi) (see below) and run it. The Codec/Filter Packs list should be filled with all previous codec packs that you currently have or might have had installed at one time on your computer. Go to Start -> Control Panel -> Add/Remove Programs and find all the packs that were listed by CCCPi. (Those that were marked by CCCPi with Uninstalled are no longer on your computer, so don't look for them) Remove (uninstall) those packs. Confirm with "Yes to all" if you are asked whether to delete certain files or not. {DONE}
If you are asked wheteher you want to reboot, then reboot but after that come back to the Add/Remove programs list and keep on removing all other packs that CCCPi has listed in Codec/Filter Packs. Do not touch the Register Filter and Unregister Filter buttons! {DONE}
3. Uninstall all other individual codecs, filters you have installed separately (like DirectVobSub, ffdshow, CoreVorbis, CoreAAC, etc.) You can keep DivX or XviD if you want to, or if you plan on encoding with DivX or XviD. They won't interfere with CCCP, so don't worry. You can also uninstall them now and install them after CCCP, it doesn't matter. However, they won't be used for decoding unless you tweak some settings - read about it here. (CCCP is only a playback solution, so that's why you need to have DivX or XviD if you plan on encoding in those formats.) {DONE}
4. Reboot. IMPORTANT! Don't skip it because you're lazy. {DONE}
5. Install the CCCP. Answer "yes" when it asks you if you want to reset all settings. {DONE}
# Try reinstalling the CCCP, often this will fix the problem. {DONE}
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results are:
2 reboots out of 10, mkv files work.normally
The rest of the time, trying to play mkv files causes mplayerc to hang indefinitely .
Ive tried playing right after rebooting, and also trying to play after using computer normally for a few hours after rebooting same problem.
I get the same results w/CCCP-installed zoomplayer.