Get an icon theming program like IconPackager. Shell32 may contain a lot of icons, but very few programs are hard coded to use them. The registry has icon paths for file types, system icons, etc.

Microsoft has often modernized other parts of the OS only for an older app to throw you into a dialog box with Windows 95-era icons from shell32.dll. New vs. old Windows 95-era icons.

Since Windows 95, Microsoft has been storing their system icons for folders, devices, settings, control panels, and applications in the C:\Windows\System32\Shell32.dll file.

Fresher, previously unseen icons for common things like hibernation mode, networking, or even floppy drives can be found in the shell32.dll files in the latest Windows 10 Dev Channel preview ...