That's very suspicious. What exactly did the warning say? Perhaps there's some special and terrible hack in there somewhere that says, if you try and execute a command called "C:\Program", and that file doesn't exist, and the command's first argument starts with "Files\", then magically treat the command and first argument as if they were a single command with a space in the middle. That would be foul and nasty, but it would provide a modicum of compatibility with buggy legacy programs, and Microsoft have a history of resolving that sort of dilemma in favour of foulness and nastiness.

Peter