It's really fast so, move on.
- Run regedit.exe
- Go to HKEY_CLASSES_ROOT
- Enter in "*".
- Go to shell (create a new key if doesn't exist)
- Create a new key and rename it to "Open with YOUR APPL"(Could exist another similar key so create it at the same folder deep)
- Create another key within the previous one, (like a subfolder tree ) rename it to "command"
- Enter created command key and change "predefined field" to "C:\Program Files\YOUR APPLCATION FOLDER\APPLICATION.exe" "%1" or your route to your application folder, it's importat to keep "%1" at the final with quotes.
- Check it in Windows Explorer, right click in a random file and test that your string appear here.
Capture at the final stage:
And the check out