function DriveExists(Drive:Byte):Boolean;
var
  Drives: set of 0..25;
begin
  integer(Drives):=GetLogicalDrives;
  Result:=Drive in Drives
end;

function CheckDriveType(Drive: Byte): string;
var
  DriveLetter: Char;
  DriveType: UInt;
begin
  DriveLetter:=Chr(Drive + $41);
  DriveType:=GetDriveType(PChar(DriveLetter + ':\'));
  case DriveType of
    0:               Result:='?';
    1:               Result:='Path does not exists';
    DRIVE_REMOVABLE: Result:='Removable';
    DRIVE_FIXED:     Result:='Fixed';
    DRIVE_REMOTE:    Result:='Remote';
    DRIVE_CDROM:     Result:='CD_ROM';
    DRIVE_RAMDISK:   Result:='RAMDISK'
    else
      Result:='Unknown'
  end
end;