Clean install of XP. DVD drive shows blank CD's, but when I insert a blank DVD, it opens a "recovery disk"?

Everything works fine, except when I put a blank dvd, instead of a window for a blank disk opening, it acts like the windows recovery disk is in the drive, and you can even explore it. A blank CD works normally. What is that about? I am not a computer expert, but I am not a novice either.