Change Icons based on extension only, not the associated application.

I don't see any difference between the visual change (the app calling a refresh) and a complete restart of the PC, icons are the same. Has to be conflicting entries or windows treating some extensions differently, like stuff that can opened natively by Windows or something.

Edit: managed to make it work by adding my own custom entries like so:

.ext
- (Default) program.extention

program.extention
- DefaultIcon extention.ico
- shell
-- open
--- command program.exe

Had to try to open a file and confirm the "open with" for the changes to apply.

Edit2: made a template to do this faster:

icon changer.reg
Windows Registry Editor Version 5.00

[-HKEY_CLASSES_ROOT\.ext]

[HKEY_CLASSES_ROOT\.ext]
"PerceivedType"=""//text/vid/etc...
@="prog.ext"
"Content Type"=""

[-HKEY_CLASSES_ROOT\prog.ext]

[HKEY_CLASSES_ROOT\prog.ext]
@="ext description"

[HKEY_CLASSES_ROOT\prog.ext\DefaultIcon]
@="C:\\Users\\abc123\\Pictures\\Icons\\ext.ico"

[HKEY_CLASSES_ROOT\prog.ext\shell\open\command] //don't forget to add the other commands, if any ...
@=""C:\\Program Files\\prog\\prog.exe""

Edit3: some default Icons are still hard to change, .exe is overwritten by something, but I don't know what.
Edit4: Had to change the default windows application icon to display my icon on .exe files. You can use CustomizeGod or some other program that can edit System Icons.

A few icons are set in the programs CLSID entry in the registry, such as .pdf and .eml icons, you can change them there if you can find the particular CLSID. I think that is what you are looking for.

Without trying it (I don't want to change things on my PC, and have never seen a request like yours) although I mentioned it earlier, it looks as if it might be possible with this or directly in the registry, as the path to the default icon appears to be recorded per extension in the registry:


If that worked, I would expect that if you were to change the default program for that extension or update the program that your personal settings would probably be overwritten.

In the case of .pdf search the registry for .pdf, that should show a key with two entries, the OpenwithProgIds entry should contain a binary value holding an Apx value such as AppXd4nrz8ff68srnhf9t5a8sbjyar1cr723, searching the registry for that key shows three keys, Application, Default Icon and Shell. The Default Icon key may well contain a path to the .pdf icon file/ resource, in this case : @{Microsoft.MicrosoftEdge_44.19041.1023.0_neutral__8wekyb3d8bbwe?ms-resource://Microsoft.MicrosoftEdge/Files/Assets/MicrosoftEdgePDF.png}, in the case of .eml the Default Icon path is : @{microsoft.windowscommunicationsapps_16005.13426.20920.0_x64__8wekyb3d8bbwe?ms-resource://microsoft.windowscommunicationsapps/Files/images/eml.png}.
These values may be different on your system though. Interestingly the Shell folder lists the commands to display those file types, often referring to a further application by it's CLSID.
It's been a while since I messed with any of this as things change so often it becomes a bit of a nightmare to keep up with it, and the registry is a rabbit hole I would rather avoid in my old age.