.ino files not opening in IDE

[Terrypin]

Today .ino files are strangely opening in an external editor (Notepad++), not the IDE. I found this thread

Arduino IDE won't load a sketch into the editor

I have been working on a project in Arduino IDE version 2.0.4. It is a rather large project with about 30+ files. Last night I restarted the IDE after many weeks of continuous running, and it refuses to open the project sketch. It opens a brand new blank sketch every time. It does open other, smaller projects, but not the one I am working on. Any pointers how to fix this is appreciated. This is on Windows 10. Windows Feature Experience Pack 120.2212.4190.0 It had been working okay, until I res…

I had some difficulty finding 'the Arduino IDE installation folder' but believe it's this:
C:\Users\terry\AppData\Roaming\arduino-ide

and followed instructions from @ptillisch to use the command
& ".\Arduino IDE"
in PowerShell. But at Step 6, executing that PS script, I got this error message:

PS C:\Users\terry\AppData\Roaming\arduino-ide> & ".\Arduino IDE"
& : The term '.\Arduino IDE' is not recognized as the name of a cmdlet, function, script file, or operable program.
Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
At line:1 char:3

• & ".\Arduino IDE"

• + CategoryInfo          : ObjectNotFound: (.\Arduino IDE:String) [], CommandNotFoundException
  + FullyQualifiedErrorId : CommandNotFoundException

[camsysca]

This posting of yours is in the IDE 1.x area. Yet you quote a 2.x fix - which IDE are you having difficulties with?

[Terrypin]

You're right, I'm using 1.8.19. Didn't spot the distinction.

But I've now tried various other 'fixes' without success. For example, the most familiar way of associating file extensions: right-clicking on an .ino file and selecting Open with.. > Arduino IDE. gives this 'Incorrect Function' error :

Same with all sketches. Only method that works is opening from the IDE itself, with File > Open.

[sonofcy]

Move your sketches folder to a non-cloud directory. Make sure your file association for .ino files is set up to open the IDE.

[Terrypin]

@sonofcy

Make sure your file association for .ino files is set up to open the IDE.

As mentioned, that fails.

More info: I unistalled Notepad++ (which I rarely use). But now, instead of opening every .ino in Notepad, I get the message shown in my last post.

[sonofcy]

Try doing an uninstall (It is Windows, right? Then use the uninstall Windows provides, do NOT do anything manually)
Now do an install and see what happens.

[Terrypin]

Yes, Win 10.
It's rare anyway, but I'm always reluctant to uninstall an app that's been running sweetly for several years. Irrational, but...

Anyway I did a clean uninstall (I use Revo Uninstaller) and then re-installed ... and all seems OK at first sight. Trust I won't get any hassle about drivers, cores, etc. We'll see.

Thanks for your encouragement!

[sonofcy]

The only thing that may pop up is drivers but it's also unlikely the uninstaller would touch them. At some point the install of another app took over the 'ownership' of the .ino files. Why it gave you that wierd message though is a new one on me.
If a driver is missing, you will find out on an upload. Don't panic, just use a magnifying glass to determine what chip is on the board closest to the USB connector and ask AI where to get the driver. The 3 most likely will have something like CH340G.
There are a few special cases, but just ask ChatGPT the following

what windows drivers does the arduino ide need