Получаем информацию о геометрии диска

 Код Delphi:
// Пробуем открыть
   hDevice := CreateFile(PChar('\\.\PhysicalDrive'+IntToStr(Drive)),GENERIC_READ, FILE_SHARE_READ or FILE_SHARE_WRITE,nil,OPEN_EXISTING,0,0);
   if hDevice = INVALID_HANDLE_VALUE then
    begin
     ToLog('Ошибка выбора диска');
     inWork:=false;
     ListBox1.Enabled:=true;
     ButtonStart.Caption:='Start';
     Exit;
    end;
   // Читаем геометрию диска
   if not(GetDiskGeometry(hDevice,DiskGeometry)) then
    begin
     ToLog('Ошибка получения геометрии диска');
     inWork:=false;
     ListBox1.Enabled:=true;
     ButtonStart.Caption:='Start';
     Exit;
    end
   else
    begin
     ToLog('Цилиндров: '+IntToStr(DiskGeometry.Cylinders));
     ToLog('Тип носителя: '+IntToStr(DiskGeometry.MediaType)+' ('+DecodeMediaType(DiskGeometry.MediaType)+')');
     ToLog('Дорожек на цилиндр: '+IntToStr(DiskGeometry.TracksPerCylinder));
     ToLog('Секторов на дорожку: '+IntToStr(DiskGeometry.SectorsPerTrack));
     ToLog('Байтов на сектор: '+IntToStr(DiskGeometry.BytesPerSector));
    end;
   CloseHandle(hDevice);

 Код Delphi:
function TForm1.DecodeMediaType(mt: byte):string;
var s: string;
 begin
  case mt of
   $00: s:='Неизвестный тип носителя';
   $01: s:='A 5.25" floppy, with 1.2MB and 512 bytes/sector';
   $02: s:='A 3.5" floppy, with 1.44MB and 512 bytes/sector';
   $03: s:='A 3.5" floppy, with 2.88MB and 512 bytes/sector';
   $04: s:='A 3.5" floppy, with 20.8MB and 512 bytes/sector';
   $05: s:='A 3.5" floppy, with 720KB and 512 bytes/sector';
   $06: s:='A 5.25" floppy, with 360KB and 512 bytes/sector';
   $07: s:='A 5.25" floppy, with 320KB and 512 bytes/sector';
   $08: s:='A 5.25" floppy, with 320KB and 1024 bytes/sector';
   $09: s:='A 5.25" floppy, with 180KB and 512 bytes/sector';
   $0A: s:='A 5.25" floppy, with 160KB and 512 bytes/sector';
   $0B: s:='Removable media other than floppy';
   $0C: s:='Fixed hard disk media';
   $0D: s:='A 3.5" floppy, with 120MB and 512 bytes/sector';
   $0E: s:='A 3.5" floppy, with 640KB and 512 bytes/sector';
   $0F: s:='A 5.25" floppy, with 640KB and 512 bytes/sector';
   $10: s:='A 5.25" floppy, with 720KB and 512 bytes/sector';
   $11: s:='A 3.5" floppy, with 1.2MB and 512 bytes/sector';
   $12: s:='A 3.5" floppy, with 1.23MB and 1024 bytes/sector';
   $13: s:='A 5.25" floppy, with 1.23MB and 1024 bytes/sector';
   $14: s:='A 3.5" floppy, with 128MB and 512 bytes/sector';
   $15: s:='A 3.5" floppy, with 230MB and 512 bytes/sector';
   $16: s:='An 8" floppy, with 256KB and 128 bytes/sector';
   $17: s:='A 3.5" floppy, with 200MB and 512 bytes/sector. (HiFD)';
   $18: s:='A 3.5" floppy, with 240MB and 512 bytes/sector. (HiFD)';
   $19: s:='A 3.5" floppy, with 32MB and 512 bytes/sector';
  end;
  DecodeMediaType:=s;
 end;

 Код Delphi:
Drive:= ListBox1.ItemIndex;

 Код Delphi:
interface
// ...
const
    IOCTL_DISK_GET_DRIVE_GEOMETRY = $70000;
 
type
    TDiskGeometry = packed record
      Cylinders: Int64;           // количество цилиндров
      MediaType: DWORD;           // тип носителя
      TracksPerCylinder: DWORD;   // дорожек на цилиндре
      SectorsPerTrack: DWORD;     // секторов на дорожке
      BytesPerSector: DWORD;      // байт в секторе
    end;    
// ...
implementation
// ...
function TForm1.GetDiskGeometry(hDisk: Cardinal; var DiskGeometry: TDiskGeometry): boolean;
var BytesReturned: DWORD;
    Res: boolean;
 begin
  Res := DeviceIoControl(hDisk,IOCTL_DISK_GET_DRIVE_GEOMETRY,nil,0,
    @DiskGeometry,SizeOf(TDiskGeometry),BytesReturned,nil);
  Res := Res and (BytesReturned = SizeOf(TDiskGeometry));
  GetDiskGeometry:=Res;
 end;

 Код Delphi:
procedure TForm1.UpdateList;
var Drive: byte;
    hD: Cardinal;
    DG:TDiskGeometry;
 begin
  Drive:= 0;
  ListBox1.Items.Clear;
  repeat
   hD := CreateFile(PChar('\\.\PhysicalDrive'+IntToStr(Drive)),GENERIC_READ, FILE_SHARE_READ or FILE_SHARE_WRITE,nil,OPEN_EXISTING,0,0);
   if (hD=INVALID_HANDLE_VALUE) then
    break;
   GetDiskGeometry(hD,DG);
   CloseHandle(hD);
   ListBox1.Items.Add('\\.\PhysicalDrive'+IntToStr(Drive)+' - '+DecodeMediaType(DG.MediaType));
   if ((DG.MediaType=11) or (Drive=0)) then
    ListBox1.ItemIndex:=Drive;
   Drive:=Drive+1;
  until (Drive=255);
 end;

 Код Delphi:
procedure TForm1.ChangeDevice(var Msg: TMessage);
 begin
  UpdateList;
 end;

 Код Delphi:
TForm1 = class(TForm)
// ...
    procedure ChangeDevice(var Msg: TMessage); message WM_DEVICECHANGE;
// ...