This should help
What I found very successfull to play all files is the K-lite Full Pack located here:
http://www.free-codecs.com/
Here are the settings to help you out
1. Bring up MCP
2. Go to View > Options
3. Select Playback > Check Auto-load load Subtitles
4. Select Playback > Output > Haali Renderer under DirectShow Video Section
5. Select Internal Filters > Check Everything in that option
6. Click OK
This is a document with screen shots to help with setting up
MCP Recommended Settings
I hope this helps and if you still encounter problems let me know.