Wrong RAM memory recognition

[CYRIX]

I recently added 4 GB DDR-2 to a motherboard, the modules are 4 boards, 1 GB each, and all four boards are exactly the same brand and frequency. But the problem is that on the POST SCREEN it shows that the total RAM memory is 2.5 GB, but in the BIOS it shows that the total RAM memory is 4 GB... I can't understand why this problem is happening...

By the way, it shows the same result when he loads WINDOWS-8.1 ENTERPRISE, given that the operating system is 64 bit! I read on the internet on other forums that this problem with recognizing all the RAM memory could be solved only by installing some server version of WINDOWS... I removed 8.1 ENTERPRISE and installed WINDOWS SERVER 2008 R2 and of course the operating system is again 64 bits, but when I right click on the icon My Computer / Properties / System again it shows that the RAM is 2.5 GB

So even though i installed a server version of WINDOWS SERVER 2008 R2 64 bits when it loads the OS it keeps showing in System that the total memory is only 2.5 GB

Actually I can't use total RAM 4 GB... only 2,5 GB are usable

I hope that someone with more experience, to help.
Thanks in advance.

Motherboard: Asrock Conroe 1333-DVI/H

Socket - 775

Chipset:

North Bridge: Intel Lakeport-G i945G

South Bridge: Intel 82801GB ICH7

CPU - Intel Core 2 Duo E8400 / 3,00 GHZ

Videocard: Nvidia Geforce 8600 GT/ video memory 1 GB

RAM MEMORY - 4 tiles, Hynix DDR2-800 (400 MHZ)

 

[ssjwizard]

From the manual at https://www.asrock.com/mb/Intel/ConRoe1333-DVIH/

- 4 x DDR2 DIMM slots*
- Supports DDR2 667/533 non-ECC, un-buffered memory
- Max. capacity of system memory: 4GB**

*Before you install memory module on this motherboard, please read below message to avoid any improper installation:

» Due to chipset limitation, if you plan to install three or four memory modules on this motherboard, please install only single-sided memory modules.
» To install two memory modules on this motherboard, please install them on DDRII_1 and DDRII_3 DIMM sockets.

For the detailed installation information, please refer to the user manual or quick installation guide.

**Due to the chipset limitation, the actual memory size may be less than 4GB for the reservation for system usage under Windows® XP, Windows® XP 64-bit, Windows® Vista™ and Windows® Vista™ 64-bit.

Can you provide the part # for the RAM modules you have installed?

 

[JLK03F150]

Another thing to check in BIOS is how much memory is reserved for vram for the onboard graphics. You want to set that to zero or as close to zero that's allowed.

 

[freeagent]

Back then I had a hard time running 4x sticks. By hard I mean it was impossible for me lol. The last time I tried for 775 was on a Rampage Formula DDR2 board. This is when my hatred for Corsair began