SD.mkdir produces file not folder?

I’ve got a micro sd card reader hooked up and I’m able to read/make files on it no problem. Directories however, don’t seem to make actual directories, they seem to be just files when I open and read the card on a windows machine… Is this correct that I won’t be able to actually explore directories created on the SD card from windows machine?

http://pastebin.com/wFxVxgW0 = my code

Thanks in advanced.

Never mind.
Solution was to format the SD card to FAT32.

Now my folders are showing up as actual directories I can now explore.