windows 8 - 4 GB of RAM, only 2.67 GB usable

My laptop was using a 2 GB RAM and I thought it wasn't enough, so I bought a new 4 GB RAM stick. I have been playing graphic and memory-intensive games, such as Battlefield 4 (the Recommended requirement for RAM is 8 GB, while 4 GB is at Minimum requirements). I have heard from the internet that the BIOS automatically 'locks' part of your available RAM into dedicated or shared video memory.

I checked the display adapter and the page shows:

--- Adapter Information ---
Chip Type: Intel (R) HD Graphics Family
DAC Type: Internal
Adapter String: Intel(R) HD Graphics 3000
Bios Information: Intel Video BIOS
Total Available Graphics Memory: 1140 MB
Dedicated Video Memory: 32 MB
System Video Memory: 0 MB
Shared System Memory: 1108 MB

As you can see, the Dedicated is at default value while the Shared System Memory is at 1108 MB (which is 1.08 GB) and I'm pretty sure the 1.08 GB is from my main RAM. I have tried accessing BIOS and I couldn't find the option to adjust Shared System Memory. Before this whole 2.67 GB usable RAM happened, I was able to play the game smoothly, but now it becomes more laggy.

I have also searched the internet regarding this issue, but all I got are those either the users were using 32-bit version of Windows (which only lets you use 3 to 3.5 GB of RAM, my system specs is at the end of this description), or about RAM address or something. I'm sorry if this question is a duplicate because I couldn't find the answers for all the searches I've done.

--- MY SYSTEM SPECIFICATIONS ---
OS: Windows 8, 64-bit
HDD: 500 GB Hard drive space
CPU: Intel Core i5-2410M, 2.3 GHz (dual core)
RAM: 4 GB (2.67 GB usable)
GPU: GeForce GT520MX 1 GB

=== UPDATE ===

As requested by Daniel B, here is a screenshot of the 'Memory' tab in Resource Monitor.

=== UPDATE 2 ===

Based on the 'Memory' tab in Resource Monitor, I see that there is 1368 MB of RAM that is in Hardware Reserved. What does it do? Is it must be reserved so that system would be stable?

Answer

Ok I found the solution. I had the ' Maximum Memory ' checked and so this was the problem.

After un-checking and restarted my laptop, Windows recognised all my 8 GB RAM (to add on, I just bought another 4 GB RAM stick).

All I have to do is to:

1. Press Win + R


2. Type msconfig and press Enter


3. Go to the Boot tab


4. Click on Advanced options


5. Un-check the box Maximum memory