Asrock Wolfdale1333-D667 motherboard problem

[haulin45]

Hey all
I got problem with this motherboard .. I put 4GB ram (2gb+2gb) but it not read full 4GB Memory Ram . WHY ???? It Said "Installed Physical Memory (RAM) : Not Available"
64bit system

OS Name : Microsoft Windows 7 Ultimate
Version : 6.1.7601 Service Pack 1 Build 7601
Other OS Description : Not Available
OS Manufacturer : Microsoft Corporation
System Name : AMIRUL-PC
System Manufacturer : To Be Filled By O.E.M.
System Model : To Be Filled By O.E.M.
System Type : x64-based PC
Processor : Pentium(R) Dual-Core CPU E5400 @ 2.70GHz, 2692 Mhz, 2 Core(s), 2 Logical Processor(s)
BIOS Version/Date : American Megatrends Inc. P1.30, 2/27/2008
SMBIOS Version : 2.4
Windows Directory : C:\Windows
System Directory : C:\Windows\system32
Boot Device : \Device\HarddiskVolume1
Locale : United States
Hardware Abstraction Layer : Version = "6.1.7601.17514"
User Name : Amirul-PC\Amirul
Time Zone : Malay Peninsula Standard Time
Installed Physical Memory (RAM) : Not Available
Total Physical Memory : 3.37 GB
Available Physical Memory : 2.44 GB
Total Virtual Memory : 6.74 GB
Available Virtual Memory : 5.53 GB
Page File Space : 3.37 GB
Page File : C:\pagefile.sys

Can anyone help me ..