Installed Memory = 4GB and Usable Memory = 2GB?

[shobuddy]

I've searched on the internet but haven't found a working solution. I'm on Win 7 64-bit with 4GB (2x2)of G-Skill DDR 3 installed on a Gigabyte ga-ex58-ud3r motherboard. System properties shows 4GB installed and 2GB usable. Resource monitor shows 2GB physical memory is "Hardware Reserved". BIOS shows 2GB total memory. I've tried several things including reseating the memory sticks. When I try just one stick at a time (to test if one of the sticks are bad), the system does not boot at all. I've made sure my maximum memory under boot options is unchecked and also verified I have the latest bios.

Graphics card properties shows the following
Total Available Graphics Memory: 1279MB
Dedicated Video Memory: 512MB
System Video Memory: 0MB
Shared System Memory: 767MB

BIOS shows the following
Base Memory: 640K
Extended Memory: 2046M
Total Memory: 2048M

The memory is: http://www.newegg.com/Product/Product.aspx?Item=N82E168...
They are in slots 1 & 3. Have also tried 1 & 4.
CPU is an i7 920 @ 2.66ghz

Anyone know whats up with the missing 2GB and how to recover it?

 

[shobuddy]

Figured out the issue. The first slot on my MB has gone bad.

 

[tcsenter]

According to the manual, population rules for two modules should be:

DDR3_#1 and DDR3_#2
or
DDR3_#1 and DDR3_#4

The slots are staggered not in consecutive order starting nearest the CPU: #1_#3_#2_#4_

 

[shobuddy]

According to the manual, population rules for two modules should be:

DDR3_#1 and DDR3_#2
or
DDR3_#1 and DDR3_#4

The slots are staggered not in consecutive order starting nearest the CPU: #1_#3_#2_#4_

tcsenter, thanks for the response. You are correct, however, my DDR3_1 slot is dead. Given that, whats the best configuration for my 2GBx2GB memory sticks? I'm currently using the 3rd and 4th slots in order. Loosing the first (DDR3_1) slot I think just causes me to loose the dual or 3 channel options, correct? Outside of that, placing the sticks randomly does not cause any problems, right?