Open/save dialog folder icons

The folder icons in SOME open/save dialogs are the ones from Windows 7 (ON Windows 7) even though I've replaced the folder icons with the ones from Win98.

I know this is a common problem but I don't really remember how to fix it.

Do you have to modify the shell32.dll file?
Or imageres.dll?

I don't really want to do that since Virtual Box only works with the untouched, unmodified shell32.dll file.

I've searched the registry up and down in order to find the place where this setting is saved (because it's gotta be saved somewhere, which icon is used in open/save dialog boxes).