i found this great program that extracts resources from .dll and .exe files, and i was wondering, if i extraced icons from windows files (ie shell32.dll) would i be able to legally use them in other programs that i write?
Yes I agree, you probably can't use them, but you could always just make your own icons from picture and use them. Just do a Google search for an icon creating program, I think there are even website that do it for free as well.
