http://msdn.microsoft.com/en-us/library/cc300158(v=vs.85).aspx Minimum supported client = Windows Vista with SP1 Minimum supported server = Windows Server 2008 MsgBox(0, "Title", "GetPhysicallyInstalledSystemMemory = " & _GetPhysicallyInstalledSystemMemory()) Func _GetPhysicallyInstalledSystemMemory() $aRet = DllCall("Kernel32.dll", "int", "GetPhysicallyInstalledSystemMemory", "uint64*", "") If @error Then Return SetError(1, 0, 0) Return $aRet[1] EndFunc Okay, we are not checking the