File associations can usually also be set (or changed) by right-clicking a file of that type, choosing Open or Open with, then selecting the application, browsing to the application if necessary. But sometimes that process fails.
The most common cause of this failure is incorrect registration of the application, particularly when a different version of the application was installed previously. To correct this problem:
- Click start; type "regedit" to find it; then right-click the program and Run as administrator.
- Navigate Computer > HKEY_CLASSES_ROOT > Applications, and find the application exe.
- Navigate shell > open > command, and check the exe path in the (Default) string.
- If the path is not correct, change it to the correct path of the application exe.