I may be able to help,

Open any folder, it doesn’t matter which one you just need explorer to open.
At the top of the open window select “tools”>”folder options”

Then click on the “file types” tab. Now scroll down to the known extensions such as .avi, .wmv, .mp3, .mp4, .mpg or whatever file type you’re trying to play and select them and in the lower portion of the box select change.

Now you are going to search for where VLC is installed on your system, and once you have changed the ones you wanted then choose “ok” or “apply” then “ok”. Now VLC should be the default player for those file types you selected instead of Media Player 11.

If you’re not sure what the file type is that you’re trying to play then pop in the dvd, open “My Computer” find the dvd drive and right click it and select “explore” find the video file and make a note of it so you can change the extension mapping as described above.

I hope this helps you, have a blessed day