Windows 8 .Mod files wont open- Please Help Thread

So i downloaded Crusader Kings 2 mod and when i went to run the .mod file it opened in cmd, and worked fine, but then i went to open it later and Windows asked me to pick a default program for all .mod files. I cant seem to go back, and am currently stuck. Thank you in advance for any advice.

You should look for the solution over to the Paradox Interactive forums, especially in the CK2 support forums.