"says Windows cant find
Are you sure - it wouldn't normally have .exe.exe on the end - it'll never find it if that's really what it's looking for.
I vaguely remember there's some software where you can tell the keyboard exactly what you want it to do for each key. I'm pretty sure you must be able to set that up somewhere, as the keyboard as standard would not be looking for Foxmail.
So change the reference to where the program really is.