The forward slash (/) as a directory separator has always been acceptable to NT. One source says that it's been acceptable to DOS since DOS 2.0, although I don'

The forward slash (/) as a directory separator has always been acceptable to NT. One source says that it's been acceptable to DOS since DOS 2.0, although I don't have a lot of backing on that. The only place that / as a directory separator doesn't work is when interpreted by cmd, as it's then ambiguous with DOS-style switches. And even then, modern cmd tries to understand / properly when possible. Most of the time it works as long as it is not the first character of a path (which you would not frequently see in Windows anyway), as there's then no way to tell it apart from a switch with a long name. The canonical representation of paths in Windows uses a backslash, but 95% of the time the slashes are interchangeable.