Windows provides no option to reset the .exe file associations, and you’ll have to do this manually.
For example, one of our readers accidentally associated executable files using Notepad, and this caused Notepad to open every time when a program was launched.
When you use the Open With dialog to associate .exe files with another application, the settings are stored in the following registry key:
HKEY_CURRENT_USER \ Software \ Microsoft \ Windows \ CurrentVersion \ Explorer \ FileExts \ .exe \ UserChoice
Note that despite this problem, you should be able to launch applications by double-clicking on the data files. For example, with the above setting, you should be able to launch Microsoft Word application by double-clicking on a .doc file, but not by running Winword.exe directly.)
ResolutionYou need to delete the UserChoice key above using a REG file or a script. Download exefix_cu.reg, and save it to Desktop. Right-click on the REG file and choose Merge.
(Hint: To undo the Open With setting for other file types, the registry location is the same. Replace the text .exe in the above registry path with the actual file extension.)
HKEY_CURRENT_USER \ Software \ Microsoft \ Windows \ CurrentVersion \ Explorer \ FileExts \ .xyz \ UserChoice