Typically, when double-clicking on any file from Windows Explorer the application associated with this type of file should start up and open the selected file automatically. When this does not happen there may be an issue relating to the file association. The following error messages may appear depending on the operating system being used.
Windows 7 / Vista
Windows 8
The following solutions provided by Microsoft for changing the Windows file association may be of assistance.
Changing File association in Windows XP.
Changing File association in Windows 7/Windows Vista.
Changing File association in Windows 8.
Changing File association in Windows 10
Outside of manually changing the file association, as explained above, you have a few options to correct the situation:
Select "Change" from "Add and Remove Programs" for MicroStation, then go through the prompts. This should re-establish file association if it was originally enabled with the install.
This should update the file association to open the DGN in MicroStation when double-clicked.
In Windows 7/Vista, you may need to right click and select "Open With > Choose Default Program" , then select "MicroStation..." from "Recommended" applications. Be sure to enable "Always Use the select program to open this kind of file".If you do not have the MicroStation.msi on your machine, or do not know where it's located you can go to "Add/Remove Programs" and select "uninstall > change", then start at step 2 above.If "File associations" is already installed, you should select "Entire feature will be unavailable" and then repeat the steps to add it again.
In Windows 7/Vista, you may need to right click and select "Open With > Choose Default Program" , then select "MicroStation..." from "Recommended" applications. Be sure to enable "Always Use the select program to open this kind of file".
If you do not have the MicroStation.msi on your machine, or do not know where it's located you can go to "Add/Remove Programs" and select "uninstall > change", then start at step 2 above.
If "File associations" is already installed, you should select "Entire feature will be unavailable" and then repeat the steps to add it again.
This should work if the file association was altered after MicroStation was installed. This should return the association back to what it was when it was created.
If it is still not opening MicroStation as it should...
If "%1" is not in the path, MicroStation will start but not open the selected file.
Example: "C:\Program Files\Bentley\MicroStation\ustation.exe" "%1"
The following answer provided from the Microsoft Answers pages relates to an issue with the associations for default programs in Windows 7 (possibly just 64 bit). Try the suggested procedure of modifying the Registry using "regedit". If you are unsure about editing the Registry you should get your IT support person to investigate this. Also, please ensure you make a copy of your registry before you make any changes.
http://social.answers.microsoft.com/Forums/en-US/w7files/thread/8a84fcec-22df-4942-8e35-d98dbe96e327
1. Navigate to \Computer\HKEY_CLASSES_ROOT\Applications and find your .exe name, ie. MicrostationDesignFile
2. Expand this a couple of levels to show "shell" and under that "open" and "print".
3. Expand another level to show "command" where you will see the location of the "ustation.exe" being used as the default program.
4. Right click on this and select Modify. Change this to the correct location for your "ustation.exe".
ie. C:\Program Files\Bentley\Microstation (Select Series 2)\Microstation\ustation.exe "%1"
The Windows operating system manages all file associations. The only time that MicroStation can affect this is during installation. If the two methods above did not help, it is likely that the problem is caused by either:
A Windows policy stopping you from changing file associations in your registry.
OR
A potentially more serious problem with your windows profile.
For this, you should seek help from Windows support (or your IT team if you have one), to address this issue. Bentley Technical Support will not be able to correct this.
https://support.microsoft.com/en-us/help/4028161/windows-10-change-default-programs