I installed Visual Studio 2012 yesterday and during the install my path somehow got screwed up¹. Since then, the icons for applications that are part of Windows are the default "unknown" icon, but other icons are fine. The applications that the shortcuts link to launch fine when the icons are clicked on.

Taskbar:

Start Menu:

I have fixed my path, but the icons still show incorrectly.

Any ideas on how to flush what appears to be a set of cached icons?

¹ _{Something took a path of A;B;C;D; and turned it into A;B;C;D;A;B;C;D;E;F; - duplicating a large part of it to that point that no more characters were available to type in the edit box in system properties. This had the side-effect of Windows reporting that it couldn't find %windir%.}