Well ... maybe not everything. One must remember that they run on Windows/.asp which doesn't care about slash direction or capitalization. \Pics\9and10news.gif is the same as \PICS\9AND10NEWS.GIF is the same as /pics/9and10news.gif to them.
However, on a *nix/Apache system that's not the case. All of those are different files and filepaths. Best practice is to use all lower-case folder/directory and file names. Also make abso-dam-lutely sure you are using / instead of \ in your file paths. Larnt both the hard way years ago. I even use lower-case names for files that will only be used on Windows systems just to be sure.