Procedure CheckFor_Medium(Drive.s) ; Узнаём есть ли диск. 1 - есть; 0 - нет
  Drive=Left(Drive,1)+":\"
  
  VNB.s=Space(100)     ; Volume Name Buffer 
  VNS=100             ; Volume Name Size 
  VSN=0               ; Volume Serial Number (Hex) 
  MCL=0               ; Max.File Name Len 
  FSF=0               ; File System Flags 
  FSNB.s=Space(100)    ; File System Name Buffer (FAT/NTFS usw) 
  FSNS=100            ; File System Name BufferSize 
  
  GetVolumeInformation_(Drive,@VNB,VNS,@VSN,@MCL,@FSF,@FSNB,FSNS) 
  If VSN<>0 : VSN=1 : EndIf
  ProcedureReturn VSN
EndProcedure

Procedure FindDisc()
Protected TypeDisc.s=""
ClearGadgetItems(0)
x=0
For n=0 To 26
  Disc.s=Chr(67+n)+":"
  If CheckFor_Medium(Disc)
    If GetDriveType_(@Disc) = 2
      AddGadgetItem(0,-1,Disc)
    EndIf
  EndIf
Next n

EndProcedure

OpenWindow(2,0,0,100,50,"",#PB_Window_MinimizeGadget|#PB_Window_ScreenCentered)
ComboBoxGadget(0,10,10,80,22)
FindDisc()
SetGadgetState(0,0)
Repeat

Until WaitWindowEvent()=#PB_Event_CloseWindow