NEW NEWS
In fact it does open on on another computer.
In fact in opens ok, if I copy it to the desktop!

But if I delete the file from the folder I usually keep it and and drag the one on the desktop that is opening ok back to the normal folder I keep my list in, then it's locked again (read only).

This is still a problem because this is the folder I like to keep these list.
The folder is read/write as are the parent folders. So I'm still puzzled.
The lock message still has the fill name of the intern in the lock message.