Usable RAM is lower than amount installed

[ZhaiNo1]

Hello guys, I own an ASUS A42JC laptop and decided to upgrade my 2GB RAM to 6GB. After installing a 4G stick, my System Properties said that there are 6GB of RAM there but only 2.67GB are usable. I have tried all of these options:

- Upgrading BIOS: My BIOS was last updated at some point in 2011, and the latest BIOS I can find on ASUS's website is from 2010. I guess mine is the newest. Please correct me if I'm wrong.
- Swapping sockets and test each stick individually: Swapping sockets yielded the same result. While testing the 4GB stick, I found out that there are 4GB installed, but still only 2.67GB available.

This has led me to believe that there is a problem with my OS, and I use Windows 7 Ultimate SP1 32-bit. It would be great if someone could confirm this or help me solve my problem. Thanks in advance!

 

[ahnilated]

Remember a 32 bit OS can only use 4GB max for ram. You could have some of it reserved and some being used by onboard video.

 

[Dark Lord of Tech]

32 bit OS can only use up to about 3.75 to 4gb , you need a 64 bit OS if your system is capable.

 

[Dunlop0078]

Its your 32 bit OS. 32bit OS can use a maximum of about 4gb of ram including any video ram.