A couple things before I get started. First, this is a solution manual that worked for me and I am posting it in hopes it will help others too. Second, This should apply to all situations where not all of the RAM installed is usable. Lastly, I did this on a new computer I had just built, so I am not sure if this will work for those of you who are upgrading the amount of RAM you are using, but feel free to try. Here we go:
1) Check to see if you are using a 64-bit operating system, 32-bit operating systems only support up to 4 GB of RAM
2) Set your maximum RAM to "nothing." Go to Start -> Run -> Without the quotations, type "msconfig" -> Click the "boot" tab -> Advanced Options -> Make sure the "Maximum Memory" Check box is empty (meaning no check mark). Confirm and restart your computer.
3) Upgrade your motherboard BIOS. (Refer to the manufacturers website, or call their help line)
4) Check to see if your video card (GPU) uses some of the installed RAM. I believe this is called integrated graphics? Please correct me if I am wrong.
5) Make sure your RAM is allocated in the correct slots. You should be able to find this in the motherboard's user manual
6) Check the RAM and memory slots on the motherboard for some type of debris. For example, in mine there was a white piece of sticker in the memory slots on the motherboard. If there is something there VERY carefully get it out.
7) Test each individual RAM. Refer to your motherboard's user manual and find which slot you should install RAM into if you only have one stick. Then using Memtest86 (just google this to find it) test to make sure your RAM is good.
8) Pull out the processor and check the pins. Be VERY VERY careful with this one. Take a bright light when looking over your processor's pins and look for any bent ones. If there is a bent pin then use tweezers or some other small gripping utensil and VERY carefully straighten the pin. Put the processor back in and turn on the computer.
This is everything I tried in a period of about 10-12 hours and eventually I got it. Number 8 was the one that worked for me, but I listed it last because numbers 1-7 are little things that may need to be done to your computer anyways. Hope this helps!
1) Check to see if you are using a 64-bit operating system, 32-bit operating systems only support up to 4 GB of RAM
2) Set your maximum RAM to "nothing." Go to Start -> Run -> Without the quotations, type "msconfig" -> Click the "boot" tab -> Advanced Options -> Make sure the "Maximum Memory" Check box is empty (meaning no check mark). Confirm and restart your computer.
3) Upgrade your motherboard BIOS. (Refer to the manufacturers website, or call their help line)
4) Check to see if your video card (GPU) uses some of the installed RAM. I believe this is called integrated graphics? Please correct me if I am wrong.
5) Make sure your RAM is allocated in the correct slots. You should be able to find this in the motherboard's user manual
6) Check the RAM and memory slots on the motherboard for some type of debris. For example, in mine there was a white piece of sticker in the memory slots on the motherboard. If there is something there VERY carefully get it out.
7) Test each individual RAM. Refer to your motherboard's user manual and find which slot you should install RAM into if you only have one stick. Then using Memtest86 (just google this to find it) test to make sure your RAM is good.
8) Pull out the processor and check the pins. Be VERY VERY careful with this one. Take a bright light when looking over your processor's pins and look for any bent ones. If there is a bent pin then use tweezers or some other small gripping utensil and VERY carefully straighten the pin. Put the processor back in and turn on the computer.
This is everything I tried in a period of about 10-12 hours and eventually I got it. Number 8 was the one that worked for me, but I listed it last because numbers 1-7 are little things that may need to be done to your computer anyways. Hope this helps!