Tak už jsem něco našel: http://www.computerperformance.co.uk/vbscript/wmi_m emory.htm

' Memory.vbs
' Sample VBScript to discover how much RAM in computer
' Author Guy Thomas http://computerperformance.co.uk/
' Version 1.3 - August 2005
' -------------------------------------------------- -----'
Option Explicit
Dim objWMIService, objComputer, colComputer
Dim strLogonUser, strComputer

strComputer = "."

Set objWMIService = GetObject("winmgmts:" _
& "{impersonationLevel=impersonate}!\\" _
& strComputer & "\root\cimv2")
Set colComputer = objWMIService.ExecQuery _
("Select * from Win32_ComputerSystem")

For Each objComputer in colComputer
Wscript.Echo "System Name: " & objComputer.Name _
& vbCr & "Total RAM " & objComputer.TotalPhysicalMemory
Next

WScript.Quit

' End of Sample Memory WMI / VBScript

Pavel