This can be any drive letter as the scripts looks for an instance of that file. (strCd & "\win51"), strCd is the array that holds the drive letters for CD or DVD drive. Here how I tested the script, I first place a XP Cd in my real drive then it copy it to the XPCD, I then ejected the CD and mounted a ISO image of XP in a Virtual drive the script reported the real CD drive as incorrect but started the copy from virtual drive next. So the drive letter does not matter as it will go threw all CD or DVD drive letters. Until a true statement exists, if nothing is found then the script will keep reporting Incorrect CD until all the CD or DVD drives in the array are finished.