Sounds like you are running under Windows.
InDesign has had a bug for over 10 years (if not longer) wherein if you install a new version and then delete any previous version, you lose file associations. A fix is supposed in the works.
To repair your file associations you must total uninstall InDesign 10 (CC 2014) and then reinstall it.
Yes, this is a royal pain in the tuchas!
- Dov