Can't make Musescore 3 default program

• May 10, 2024 - 03:29

I recently downloaded Musescore 4 to finally try it out. I decided I prefer to stick with MS3 but I'd keep MS4 just to convert new files for MS3.
My problem is that files open with MS4 by default and none of my attempts to make MS3 the default have worked (I'm using Windows 10 by the way).
I have tried:
1.) changing the default app in the 'right-click, properties menu' of a MS file. It ignored the change.
2.) navigating to the 'right-click, open with, choose another app, always use this app' method. It also ignored the change.
3.) Finally, I gave up and just uninstalled MS4 but even now, when double clicked, it tries to open it with MS4 and asks me to choose a different program since it can't find the deleted file. The attached picture shows this.

I apologize if this is more of a Windows problem than a MS problem but I'm hoping someone else has already solved this issue.

EDIT: I solved the problem by uninstalling all Musescore versions and deleting the remaining registry files

Attachment Size
Musescore opening problem.png 47.13 KB


Uninstalling MU4 doesn't get rid of everything. That's part of it. But for now, you should be able to right click on a MU3 file and select MU3 to open it. This isn't a universal change. Only file by file. Unless you had opened the MU3 file In MU4, then it is a different procedure.

For Windows 10, try this...
Press 'Start' button then select 'Settings', then select 'Apps', then select 'Default apps', then select 'Choose default apps by file type' where you scroll through all file types until you find .mscx, .mscz, etc. and set the default app to MuseScore 3.

The solution 1 and 2 you're mentioning should definitively work.
There is a serious problem with your windows registry or you are not clicking exactly on the correct option.
You can paste a screen capture of what you are trying here if you want, we'll have a look to better help you.

Your picture doesn't match your issue description. Your picture shows that Windows is going to open MS3. What happens if you click "OK" to "Keep using this app"?

As mentioned above, your Windows registry could be broken. Have you tried re-installing MS3? If this doesn't work then you can:
(1) Uninstall all MuseScores
(2) Use RegEdit to remove any references to MS from your Windows registry.
(3) Re-install MS

Don't mess with anything else in the registry as you could unwittingly render your computer non-bootable.

In reply to by yonah_ag

Windows seems to be playing things both ways.
On one hand, it says MS3 is the default program for these files, and on the other, it asks me what program I want to use when attempting to open a file (my screenshot). When trying to "keep using the app", it reverts immediately to whatever messed up state it's in as if it never asked to begin with. I expect I will have to try your steps here.
And thanks for the 3.7 recommendation

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