Thanks but that's still too vague to be actionable.
> My guess is that if you were to install TextPad then it would
> start working, since I have TextPad on all my machines, and may
> not have tested in the absence of TextPad.
Actually I do have TextPad and I get: "Cannot find key
'TextPad\shell\open\ddeexec\application' in registration
database (error 2)" which, as I said in my first email, is
the same error that I get when trying "winhugs /edit" from
the command line. I speculated that was the command because
that is the HKEY_CLASSES_ROOT\hugs_haskell\shell\Edit\command
key but it is clear that more happens under the cover after that.
Under Options, TextPad is already the selected editor, so that
doesn't help me. The (grayed out) command is "C:\Programme\
Textpad 5\System\DDEOPN32.EXE TextPad %s(%d)". Trying to execute
that from the Windows shell gives the same error as above.
I think the mistake is to look for a TextPad entry: there
isn't one. Instead there are Textpad.dde and TextPad.tws
entries and I guess Textpad.dde is the correct one since it
has the shell\open\ddeexec\application key. But whose mistake
is it: TextPad's or WinHugs' and how does one go about fixing it?