How do I get kana if I don't have a Windows disc?
 

I got my computer used so I didn't install Windows myself; they did it at the store for me. I guess they didn't think having Asian alphabets was relevant, because they didn't include it, and when I tried to add it I was prompted to insert the disc to do so.

Is there a way to install kana without a Windows disc? Someplace I can download it or something? I'm tired of going to pages I used to be able to read and just seeing little boxes instead of words. :(