Sign up ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I am attempting to set the default program to open a file with and I am unable to do so. I am using Windows 7 and the file extension I am attempting to set a default program to is bfa (*.bfa); the program that not only generates this file type but also the program which I am attempting to set as the default to open it is Blowfish Advanced CS (

When I right click a file and select "Open With", I go through the motions of trying to select the program: clicking "Browse" with "Always use the selected program..." checked and then I browse to the program. Once I select the program it fails to pop up as an option in the "Open With" dialog. I suspect the problem relates to the fact that the OS is 64-bit and application is 32-bit. Any suggestions on how to proceed?

share|improve this question
I had this happen when upgrading from a 32-bit to a 64-bit version of an app. Because 64-bit apps are stored in a different Program Files folder, Windows couldn't find it and so wouldn't let me select it. I fixed the problem by going through the registry and deleting all references to the 32-bit version. – Adam Pierce Jun 26 at 3:44
I recently had a similar problem with the program Geogebra and in my case I solved it by renaming the executable. But I am not sure what is causing this issue, maybe windows has some kind of duplicate name of an executable of a previous version of that program, even though the path name is different. – fibonatic Jul 22 at 16:04

8 Answers 8

I had similiar problem, when I upgraded from Sublime Text 2 to Sublime Text 3. Navigate to Computer\HKEY_CLASSES_ROOT\Applications\ find the key for (application name) and just delete it. Then do the Open With (default=) trick again, and it all works. – zipzit Nov 14 at 23:40

This is close to the correct solution. Find the application key, lets say for Notepad++.exe in \HKEY_CLASSES_ROOT\Applications\notepad++.exe \shell\open\command\ Check the standard value of the registry if the .exe path is right. If not, then change the path to the correct one. After doing this, you can go to the file and use the standard way Open With and choose the program you wish to open.

share|improve this answer
If some of your drive letters have changed - when you remove/add a permanent disk or changed around drive letters, like sometimes happens when repartitioning drives - This is the most accurate and safest solution (among registry-based solutions). – Neowizard Mar 6 at 4:55
I tried the 2 other highly voted answers and was still stuck. This was the only thing that fixed it for me. – scunliffe Jul 14 at 12:44
As @scunliffe mentioned, this was the solution that worked for me. The reason I was having this problem was that I had repartitioned my disks and the default software was on a different partition with a different drive name. However, after the drive name change, the registry was still having the old path listed under the software. Changing the path to the current software path solved everything. – globetrotter Aug 17 at 10:42
one of my students had a similar problem, he opened a portable version of sublime once from our shared Network Drive, so \shell\open\command\ was set to "\\servername\studentSoftware\sublime\sublime_text.exe" even after he installed sublime locally on his laptop. so when he was not at school he chouldn't assign sublime as default program. for me this is the correct answer. – philx_x Oct 21 at 7:14

I had the same problem, and none of the solutions worked (like the above method of going to the Control Panel - which does the same thing if you right click the file->Open With->Choose Default). Even after selecting the new program many times, it was stuck with the old one.

I fixed it by editing the registry. Go to the concerned extension like this (I had problem with .cpp):


Besides these two keys: OpenWithList and OpenWithProgids, it might have a third one called 'UserChoice'. Just delete that third key. After that, it will allow you to change the default program for that file extension.

share|improve this answer
I had similiar problem, when I upgraded from Sublime Text 2 to Sublime Text 3. Navigate to Computer\HKEY_CLASSES_ROOT\Applications\ find the key for (application name) and just delete it. Then do the Open With (default=) trick again, and it all works. – zipzit Nov 14 '14 at 23:40


Control Panel\All Control Panel Items\Default Programs\Set Associations

enter image description here

share|improve this answer
Thanks, I did try this; it ultimately will end up bringing up the same "Open With" dialog. When I tried it this way it failed as well. – Gedalya Oct 7 '13 at 17:50
@Gedalya can you open the program directly and then the file within the program? and when you choose to open it with your program, what program if any does it try to open the file in? – barlop Oct 7 '13 at 18:37
I can open it directly with my program. Currently the file is associated with Adobe Acrobat; this is by accident though. When I first installed the program the file type was unassociated; when I tried to associate it it was accidentally associated with Acrobat. – Gedalya Oct 7 '13 at 18:58
so was acrobat always opening it? and you couldn't stop acrobat from opening it until you change the file association within blowfish itself? – barlop Oct 7 '13 at 20:35
No, Acrobat wasn't always opening it. I associated the file with Acrobat on accident; I went through the motions of trying to associate Blowfish and didn't pay attention to the fact that it wouldn't let me and Acrobat was selected so it ended up being associated. Acrobat doesn't really have anything to do with the problem. – Gedalya Oct 7 '13 at 21:41

I was able to fix my problem with the program itself. See the picture below for reference; under 'Tools' > 'Options'

The 'Miscellaneous' tab; under 'Registry Setup' there are two options that alter the registry. I applied both and it works now. What isn't clear is how I could have done this without the program doing this.

enter image description here

share|improve this answer
you can accept your own answer – barlop Oct 8 '13 at 21:48
The program was probably actively working against you. Every time it loaded and the 'Associate File Types' box was unchecked, it probably scrubbed the filetype association out of the registry. – Brian Dec 31 '14 at 19:36

Just for you guys to know...

I had the same problem on win8.1.

That default file dialog seems to hang explorer, it happens both from the folder´s right click option and from set association screen, I think there is some problem with that functionality...

For me, killing explorer process via Task Manager and reopening explorer, (from task manager) via File -> new Task -> explorer.exe, completed the process of setting the default program normally and everything works fine now.

I don´t know if was just luck, but it is worth trying...

share|improve this answer

The best solution is to remove the user account that cannot set a default program to open a file and re-create a new user. At some point when installing/updating an application, Windows corrupted the policy for that user account. Be sure to copy all the user's data (c:/users/userid/) before removing that user account and log in with a different user with Sysadmin account.

To Remove the user account: Control Panel >> System >> Advanced system settings >> Advanced (tab) >> Setting (under User Profile) >> delete the corrupt user account.

Then reboot, log in and create a new user. You can use the same account name.

share|improve this answer

i fixed this issue by right-clicking the file i wanted to open and choosing "properties". on the "general" tab it said "opens with: unknown program" or something like that. i just clicked the "change..." button next to that message and picked the app i origionally wanted. i think maybe this happens when the associated application gets deleted.

share|improve this answer

Try setting the default from within the program you want to use as opener.

I had similar problem when php files all of a sudden started opening with Acrobat which caused an error as Acrobat can't handle php. I tried to change the association, but all failed. Finally went to Dreamweaver's preferences and set it as opener for php.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.