Here's a simple bit of code, but watch out - lots of people have multiple CD drives (CD reader & writer, or CD and DVD), so you should allow for that in your code...
VB Code:
  1. Private Declare Function GetDriveType Lib "kernel32" Alias "GetDriveTypeA" (ByVal nDrive As String) As Long
  2.  
  3.   For i = 1 to 26
  4.     Select Case GetDriveType(chr(64+i) & ":\")
  5.         Case 2  ' "Removable"
  6.         Case 3  ' "Drive Fixed"
  7.         Case 4  ' "Remote"
  8.         Case 5  ' "Cd-Rom"
  9. ' do something here!
  10. msgbox chr(64+i) & "is a CD drive"
  11.         Case 6  ' "Ram disk"
  12.         Case Else  ' "Unrecognized"
  13.     End Select
  14.   Next i