Windows Won't Add Editor to "Choose Program" List

I select *Open With* from the right-click menu on a file. Windows won't show my *KEDIT* editor in the *Choose Program* list. I "browse" to *Kedit* in Program Files, select it but W7 refuses to add it to the *Open With* list of programs from which I can choose to associate the file. Using Control Panel *Set Your Default Program* produces the same result. I have a second W7 machine where this...