Application icons and extension changed to .LNK
1. Click run command then type regedit and press ENTER.
2. Navigate to the following registry branch:
Replace the [ext] with the actual file extension that you want to restore its file type association to revert back to original Windows 7 default (probably .lnk).
If you unsure, simply browse through all the sub-key under File Extensions.
3. Delete the sub-key named UserChoice.
4. Exit from Registry Editor.
5. Restart the system