// TMemoryStatus is a rename of _MEMORYSTATUS:
_MEMORYSTATUS = record 
  dwLength: DWORD;         {structure length}
  dwMemoryLoad: DWORD;     {an integer representing the proportion of memory used}
  dwTotalPhys: DWORD;      {total physical memory}
  dwAvailPhys: DWORD;      {Total available physical memory}
  dwTotalPageFile: DWORD; {Total virtual memory}
  dwAvailPageFile: DWORD; {Total available virtual memory}
  dwTotalVirtual: DWORD;   {Total number of addresses in the virtual address table}
  dwAvailVirtual: DWORD;   {Total number of addresses available in the virtual address table}
end ;

Make a small program to see the memory situation:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type 
  TForm1 =class (TForm)
    Memo1: TMemo;
    procedure FormCreate (Sender: TObject);
  end ;

var
  Form1: TForm1;

implementation

{$ R * .dfm}

procedure TForm1.FormCreate (Sender: TObject);
var
  m: TMemoryStatus;
const 
  num =1024 * 1024;
begin
  GlobalMemoryStatus (m);
  Memo1.Clear;
  with Memo1.Linesdo begin 
    Add (Format ('dwLength:'        + #9 + '% d', [m.dwLength]));
    Add (Format ('dwMemoryLoad:'    + #9 + '% d', [m.dwMemoryLoad]));
    Add (Format ('dwTotalPhys:'     + #9 + '% d', [m.dwTotalPhys div num]));
    Add (Format ('dwAvailPhys:'     + #9 + '% d', [m.dwAvailPhys div num]));
    Add (Format ('dwTotalPageFile:' + #9 + '% d', [m.dwTotalPageFile div num]));
    Add (Format ('dwAvailPageFile:' + #9 + '% d', [m.dwAvailPageFile div num]));
    Add (Format ('dwTotalVirtual:'  + #9 + '% d', [m.dwTotalVirtual div num]));
    Add (Format ('dwAvailVirtual:'  + #9 + '% d', [m.dwAvailVirtual div num]));
  end ;
end ;

end .