As Colin says, Windows supports "/" but prefers "\". If you want a true cross-platform answer, you should be using path.join in your code which will take care of that plus a bunch of other issues for you. That is what I recommend.
Another issues is drive letters and drive paths. Linux doesn't have drive letters and may struggle with drive paths (UNC paths).
Some versions of Windows (and some badly written Windows applications) may also struggle with path lengths and will certainly struggle with folder/file names that are valid on POSIX but not on Windows (such as ones that include : in the name for example).
So there are certainly some things you need to be cautious about but generally if you use path.join and avoid crazy file names and case-sensitive names, you should be fine 
