//声明:
GetVolumeInformation(
  lpRootPathName: PChar;               {磁盘驱动器代码字符串}
  lpVolumeNameBuffer: PChar;           {磁盘驱动器卷标名称}
  nVolumeNameSize: DWORD;              {磁盘驱动器卷标名称长度}
  lpVolumeSerialNumber: PDWORD;        {磁盘驱动器卷标序列号}
  var lpMaximumComponentLength: DWORD; {系统允许的最大文件名长度}
  var lpFileSystemFlags: DWORD;        {文件系统标识}
  lpFileSystemNameBuffer: PChar;       {文件操作系统名称}
  nFileSystemNameSize: DWORD           {文件操作系统名称长度}
): BOOL;


//举例:
procedure TForm1.FormCreate(Sender: TObject);
var
  RootPath: array[0..20] of Char;
  VolName: array[0..255] of Char;
  SerialNumber: DWORD;
  MaxCLength: DWORD;
  FileSysFlag: DWORD;
  FileSysName: array[0..255] of Char;
begin
  RootPath := 'C:\';

  GetVolumeInformation(
    RootPath,
    VolName,
    255,
    @SerialNumber,
    MaxCLength,
    FileSysFlag,
    FileSysName,
    255
  );

  Memo1.Clear;
  with Memo1.Lines do
  begin
    Add(Format('磁盘驱动器代码字符串:'+ #9#9 +'%s',[RootPath]));
    Add(Format('磁盘驱动器卷标名称:'+ #9#9 +'%s',[VolName]));
    Add(Format('磁盘驱动器卷标序列号:'+ #9#9 +'%s',[IntToHex(SerialNumber,8)]));
    Add(Format('系统允许的最大文件名长度:'+ #9 +'%d',[MaxCLength]));
    Add(Format('文件系统标识:'+ #9#9#9 +'%d',[FileSysFlag]));
    Add(Format('文件系统名称:'+ #9#9#9 +'%s',[FileSysName]));
  end;
end;


//效果图: