Windows – Changing icons for protected file extensions in Windows 10

file extensioniconswindows 10windows-explorerwindows-registry

The goal is to get .jpg, .png, .tif, and .raw files to always open with Photoshop CC 2015 and use their appropriate icons.

Example

You can refer to the flowchart below about how Windows 10 chooses an icon for a file. I came up with this by making changes in the registry and observing the results.

(click to enlarge)
Flowcart

Problems

  • If an extension is associated with a file type, the default icon defined by the extension key is ignored.
  • The file type defined by the UserChoice key ProgId value overrides the file type defined by the extension key.
  • UserChoice key ProgId value is set to Application/Photoshop.exe when setting Photoshop as the always-open-with app for .jpg and .png.
  • Can't change UserChoice key ProgId value because of new hash security
  • Can't remove UserChoice key for protected extensions like .jpg and .png

Questions/Possible Solutions

  1. Is there a way to override the icon defined by a file type on the extension level?
  2. Is there a way to override the file type defined by a UserChoice key on the extension level?
  3. What determines what the UserChoice key ProgId value will be set to when setting the always-open-with app in the GUI and why does .tif result in Photoshop.TIFFFile.90 while .png and .jpg result in Application/Photoshop.exe?
  4. Is there a way to generate the hash required on the UserChoice key?
  5. Is there a way to stop Windows from checking/requiring the UserChoice key hash?
  6. Is there a way to specify a file type like Photoshop.JPEGFile.90 as the always-open-with app using the GUI?
  7. Is there a way to stop Windows from protecting/recreating the UserChoice keys?

Notes

Registry changes wont take effect until explorer.exe is restarted/refreshed. You can use Task Manager to kill and restart explorer.exe, or you can use DesktopRefresh.exe.

The UserChoice key can exist in two places:

  • HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.jpg\UserChoice
  • HKCU\SOFTWARE\Microsoft\Windows\Roaming\OpenWith\FileExts\.jpg\UserChoice

If one does not exist, the other is used. So make sure to delete/modify them both if you want to make a change.

Example Keys:

  • extension key: HKCR\.jpg
  • file type key: HKCR\Photoshop.JPEGFile.90
  • UserChoice key: HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.jpg\UserChoice

Details

When Photoshop first installed, it associated all the file extensions and everything was great. At some point I decided I wanted to always open .png, .jpg, .tif, and .raw files with the Photos app. So I: right-click a .png/.jpg/.tif/.raw file -> Open with -> Choose another app -> Select Photos -> Check "Always open .png files with this app". Now I want to go back to opening with Photoshop. I did the same as before expect chose Photoshop as the app to always use. Now .jpg, .png, .tif, and .raw files open with Photoshop. However, .tif files show the correct icon but .jpg, .png, and .raw show the Photoshop.exe icon.

I tried reinstalling Photoshop but that did not help. I tried using Adobe Bridge to reset the File Associations but that did not help either. Tools like File Types Manager and Default Program Editor do not work (I'll explain why below).

Then I started looking into how Windows 10 chooses which icon to show for a given file. I learned:

  1. If the extension is associated with a file type, the icon defined by that file type key is used. Otherwise, the icon defined by the extension key is used.
  2. An extension can be associated with a file type two ways: If an always-open-with program/app has been set for an extension, then the program/app is used as the file type for the extension. Otherwise, a file type can be defined by the extension key.

In my case, .jpg, .png, .tif, .raw have Photoshop set as the always-open-with app. This is reflected in the registry via the

  • HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.jpg\UserChoice
  • HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.png\UserChoice
  • HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.tif\UserChoice
  • HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.raw\UserChoice

keys. This is where the difference between .tif and .jpg/.png/.raw shows. .tif has a ProgId value of Photoshop.TIFFFile.90 while .jpg, .png, and .raw have Applications\Photoshop.exe. This means that .tif is correctly associated with the Photoshop.TIFFFile.90 file type but .jpg .png, and .raw are associated with the file type Applications\Photoshop.exe.

I can't simply change the icon for the Applications\Photoshop.exe file type because .jpg, .png, and .raw all use that file type. Therefore, the same icon is used by the 3 extensions. I can't specify a unique icon for each extension. This is why the File Types Manager and Default Program Editor tools don't work. They set the DefaultIcon for the file type in this case.

The solution seemed simple: change the ProgId value in the UserChoice keys to use the Photoshop.JPEGFile.90, Photoshop.PNGFile.90, and Photoshop.RAWFile.90 file types. This is not possible in Windows 10 anymore. A new security measure adds the Hash value which accompanies the ProgId value in the UserChoice key. Only Windows knows how to generate this hash. If the hash is not correct for the ProgId value, Windows resets/removes the UserChoice key. This makes it so this value can only be set via the Windows GUI. The idea is to prevent viruses/attackers from being able to programmatically change the always-open-with app for extensions.

I have no idea why selecting Photoshop as the always-open-with app resulted in the correct ProgId being set for .tif but not for .jpg, .png, and .raw, but it does not seem possible to fix. At this point, I started looking at other extensions that I had not touched like .tga. I never set a always-open-with app for .tga, so it did not have a UserChoice key. Instead, .tga's extension key defined the associated type like so:

[HKCR\.tga]
@="Photoshop.TGAFile.90"

Another seemingly simple solution: Unset the always-open-with app by removing the UserChoice keys and define the file type on the extension keys. This worked for .raw, but not .jpg and .png. When I removed the UserChoice keys for .jpg and .png I got a Windows notification with this error:

An app default was reset

An app caused a problem with the default app setting for .jpg files, so it was reset to Photos

I refreshed the registry and, sure enough, the UserChoice key was back. It turns out that Windows protects some extensions (like .jpg and .png) and it does not let you remove the UserChoice key.

So we can't remove the UserChoice key, we can't update UserChoice.ProgId to the correct value, and we can't override the file type specified by UserChoice.ProgId… what now?

Best Answer

I figured out a hacky workaround, but I would still like to get the answers to my questions above so we can find a proper/less hacky solution.

Beginner-friendly step-by-step below.

Create a dummy .cmd file and set it as the always-open-with app for an extension using the GUI. This causes Windows to create a new file type for the dummy .cmd "app" and associate it with the extension by setting the UserChoice key ProdId value (ex: Application/customJPEG.cmd). Repeat this process for each extension using a uniquely named dummy .cmd file and, bam, we have unique file types associated with each extension (ex: Application/customJPEG.cmd, Application/customPNG.cmd, etc.). We can then customize the icon and open/edit commands independently for each new file type.

See my flowcart in the original question for more information about how Windows chooses the icon for a file.

Note: This workaround is only required for protected extensions like .jpg and .png. See my question above for solutions to non-protected extensions. However, this workaround should work for any extension regardless.


Quick vocab:

  • File extension: What comes after the final dot in a filename. .jpg, .jpeg, .png, etc. are all different file extensions.
  • File type: A file classification/category. May be associated with one or more file extensions. For example, the JPEG file type may be associated with both the .jpg and .jpeg file extensions.

Note: Image file extensions like .jpg and .png show thumbnails of the image. To see the icon, either create an empty file (so a thumbnail can't be generated) or open an Explorer window and set the View to Details.

Note: You won't see anything change until you refresh the desktop. Make sure to do this after making changes to the registry. See step 6 for details.

Note: If a key seems to be missing in the registry, try refreshing by pressing F5 or View->Refresh. regedit does not stay up to date and requires a refresh to see the latest.

Repeat the steps below for each file extension. Replace .jpg with your file extension and Photoshop with whatever app you want.

1. Create a dummy .cmd file

  1. Open Notepad
  2. You can leave the file empty
  3. File->Save As
  4. Use something like customJEPG.cmd as the filename and save

It doesn't matter where you save it or what you name it expect the name must be different for each file type. The name of the dummy .cmd will determine the name of the file type. I recommend including the extension or file type in the name so it is easy to distinguish later.

2. Set the dummy .cmd file as the always-open-with app

  1. Right-click a .jpg file
  2. Open with->Choose another app
  3. Make sure "Always use this app to open .jpg files" is checked
  4. Scroll to the bottom and click "More apps ↓"
  5. Scroll to the bottom again and click "Look for another app on this PC"
  6. Browse to and choose your dummy .cmd file
  7. Ignore and close the "This app can't run on your PC" error
  8. If the "How do you want to open this file?" window pops up again, make sure your dummy .cmd file is still selected under "Keep using this app" at the top, check "Always use this app to open .jpg files", and hit OK.

If you want multiple file extensions to share the same file type, repeat steps 1-7 above for each extension.

3. Get the new associated file type

  1. Open regedit
  2. Navigate to:
    HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.jpg\UserChoice
  3. Copy/write down the value of ProgId. This is the file type that is now associated with the .jpg extension

The file type should be Applications\{the name of your dummy .cmd}. Example: Applications\customJPEG.cmd.

4. Update the file type to use the correct icon

  1. In regedit, navigate to HKEY_CLASSES_ROOT\
  2. Now open the key with the same name as your file type. For example, if your file type is Applications\customJEPG.cmd, You will open:
    HKEY_CLASSES_ROOT\Applications\customJEPG.cmd
  3. Create a new key inside named DefaultIcon
  4. Set the (Default) value of the DefaultIcon key to a path to the icon you want to use. Example:
    E:\Tools\Adobe\Adobe Photoshop CC 2015\Photoshop.exe,30

5. Update the file type to open and edit with Photoshop

  1. Open the shell\open\command key inside your file type key. Example:
    HKEY_CLASSES_ROOT\Applications\customJEPG.cmd\shell\open\command
  2. Edit the (Default) value so that it points to your Photoshop.exe instead of your dummy .cmd file. Example:
    "E:\Tools\Adobe\Adobe Photoshop CC 2015\Photoshop.exe" "%1"
  3. Create the edit\command key inside the shell key if it does not exist. Example:
    HKEY_CLASSES_ROOT\Applications\customJEPG.cmd\shell\edit\command
  4. Edit the (Default) value so it has the same value as your open\command key. Example:
    "E:\Tools\Adobe\Adobe Photoshop CC 2015\Photoshop.exe" "%1"

6. Refresh the desktop

You will not see anything change until you refresh the desktop. There are 3 ways to do so:

  • In windows 10 run ie4uinit.exe -show. In Windows 7 and 8 run ie4uinit.exe -ClearIconCache. (Thanks to @Tony for this tip.)
  • Or, you can simply download and run DesktopRefresh.exe

  • Or, you can restart explorer.exe:

    1. Bring up the Task Manager (ctrl+shift+esc)
    2. Go to the details tab and find explorer.exe
    3. Right-click explorer.exe->End task and click End Process
    4. Still in Task Manager go to File->Run new task
    5. Type explorer.exe and hit OK

7. Test it out

  1. The correct icons should now be shown for .jpg files.
  2. Double clicking a .jpg file should open it in Photoshop.
  3. Right-click a .jpg file->Edit should open it in Photoshop.

If the "How do you want to open this file?" window pops up again, make sure your dummy .cmd file is still selected under "Keep using this app" at the top, check "Always use this app to open .jpg files", and hit OK.

8. Delete the dummy .cmd

You can delete your dummy .cmd file. This is optional.

A note about finding icons

Often, an app's .exe will contain multiple icons. For example, the Photoshop.exe contains all the icons for all the different file types it supports. Here's how to find and use these icons:

  1. Create a shortcut to the .exe by right-clicking and selecting Create shortcut
  2. Right-click the shortcut and select Properties
  3. Click the Change Icon button near the bottom
  4. You will now see a window like this (but without the numbers):
    icons Window
  5. The icons are numbered starting from 0. Find the number of the icon you want to use. Instead of counting, you can use the formula (column - 1) * 4 + row - 1. For example, if the icon is in column 6, row 3, (6 - 1) * 4 + 3 - 1 = 22
  6. Now you can reference that icon by including the number in the path to the .exe like so:
    C:\Example\Photoshop.exe,23
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