Set Program Access and Defaults from Start Menu

[cawsgt]

When I click on "Set Program Access and Defaults" from the Start Menu, I get
the error message: An exception occurred while trying to run
"shell32.dll,Control_RunDLLappwiz.cpl,,3"

What is that? Then a box comes up that says "Run a DLL as an App has
encountered a problem and needs to close.

Please help. I'm using Windows XP and Internet Explorer 8.