Get system memory information

Use GlobalMemoryStatus procedure with variable of TMemoryStatus type for getting information about memory.

procedure TForm1.Button1Click(Sender: TObject);
var
  MyStatus: TMemoryStatus;
begin
  MyStatus.dwLength:=SizeOf(MyStatus);
  GlobalmemoryStatus(MyStatus);
  with Memo1.Lines do
  begin
    Add(FloatToStr(
      MyStatus.dwMemoryLoad)+'% memory in use');
    Add(FloatToStr(
      MyStatus.dwTotalPhys/1024)+' Kb of physical memory');
    Add(FloatToStr(
      MyStatus.dwAvailPhys/1024)+
      ' Kb of available physical memory');
    Add(FloatToStr(
      MyStatus.dwTotalPageFile/1024)+
      ' Kb that can be stored in the paging file');
    Add(FloatToStr(
      MyStatus.dwAvailPageFile/1024)+
      ' Kb available in the paging file');
  end;
end;