How do i uninstall nero 7 demo off of my computer, it won't let me uninstall it.?

when i try to uninstall nero 7 demo it gets to the end then pops up a message say that "custom action DLL crashed on lat call oin function NeroAg_unregisteredComEx. installer must now exit" then it show the threds for the crash and the current. what does this mean and how do i uninstall it cause i can't download another nero until that one is off.