[[escafandra]]

¿Has tratado de probar de esta forma?

Código Delphi [-]
PERFORMANCE_INFORMATION = record
  cb: DWORD;
  CommitTotal: DWORD;
  CommitLimit: DWORD;
  CommitPeak: DWORD;
  PhysicalTotal: DWORD;
  PhysicalAvailable: DWORD;
  SystemCache: DWORD;
  KernelTotal: DWORD;
  KernelPaged: DWORD;
  KernelNonpaged: DWORD;
  PageSize: DWORD;
  HandleCount: DWORD;
  ProcessCount: DWORD;
  ThreadCount: DWORD;
end;
PPERFORMANCE_INFORMATION = ^PERFORMANCE_INFORMATION;

function GetPerformanceInfo(pPI: PPERFORMANCE_INFORMATION; cb: DWORD): boolean; stdcall; external 'psapi.dll';

//............................

var
 PI: PERFORMANCE_INFORMATION;
begin
 GetPerformanceInfo(@PI, sizeof(PI));
 ShowMessage('Memoria total: ' + IntToStr(PI.PhysicalTotal * PI.PageSize) + ' Bytes');
end;

(Probado en WinXP Sp3, Delphi7 y PC con dos módulos de memoria RAM).


Saludos.