Paint.NET replaces application icons for TortoiseHg

Question

This is confusing me a bit. I've recently set up a new PC at work and installed both TortoiseHg and Paint.NET, as usual. However, for some reason, all shortcuts to TortoiseHg are replaced with Paint.NET's application icon:

Reinstalling either application does not help, uninstalling Paint.NET does.

Clearing the icon cache by removing %LocalAppData%\IconCache.db does not help, either.

Now, all default shortcuts to TortoiseHg are shortcuts to the application itself, not a specific file path (which means I can't even change the icon of the shortcut):

My only guess right now is that perhaps Windows Installer is a bit confused about its application database, but I don't really have an idea how to verify or fix this.

The shortcut (and application icon in the registry) apparently references the icon at %SystemRoot%\Installer\{50AF3472-30AD-42C5-84FF-8A1ACE7CEFBF}\thgIcon.ico which is the correct one. {50AF3472-30AD-42C5-84FF-8A1ACE7CEFBF} is also the product GUID for TortoiseHg in the registry. So it appears that this product is correctly set up, as far as I can tell.

Answer 1

The workaround posted here did work for this case as well. Originally found that link in the issue thread for TortoiseHg and it seems to be a problem with Windows Installer shortcuts and the default application for icon files.

Answer 2

Icons in Windows Explorer are rendered (displayed) by the registered "Icon Rendering Application" object. If the "Icon Rendering Application" cannot understand the icon, it displays its own icon instead.

When Paint.NET cannot understand TortoiseHg icons, you see the Paint.NET icon instead.

Errors of this sort may be caused by a problem with TortoiseHg, fixed by re-installing TortoiseHg and clearing the icon cache, or may be caused by a problem with Paint.NET, fixed by using the file-association dialog to tell windows to use a different application to display icons (.ico files).