In acad2007: If I type this at the command line: (startapp "c:\\program files\\microsoft office\\office\\winword.exe") msword opens However, if I assign that to a button on a toolbar, it hangs at (startapp c: as if it were paused waiting for input (\) If I change to forward slashes in the button macro: (startapp "c://program files//microsoft office//office//winword.exe") the button works and msword opens Why?