Adding an option to the windows right-click menu

Question

I want to add some compile options to the right click menu. For instance, when I right-click a Haskell (.hs) file, I want to have an option "Compile with GHC". Following some instructions I found online, I went into regedit, and under HKEY_CLASSES_ROOT\.hs, I added shell\Compile with GHC\command, giving the compile command as the (Default) value for the command key. Yet nothing new appears on the right-click menu. What am I doing wrong?