procedure GetCDROMDrives(list: TStrings); 
var 
  DriveBits: set of 0..25; 
  Drives,DriveNum: integer; 
  DriveLetter: string; 
begin 
  list.Clear; 
  Drives := GetLogicalDrives; 
  if Drives <> 0 then 
  begin 
   integer(DriveBits) := Drives; 
   for DriveNum := 0 to 25 do 
   begin 
     if (DriveNum in DriveBits) then 
     begin 
       DriveLetter := char(DriveNum+Ord('A'))+':'; 
       if GetDriveType(PChar(DriveLetter)) = DRIVE_CDROM then 
         list.Add(DriveLetter); 
     end; 
   end; 
  end; 
end;