Vista x64, 8 gigs of RAM showing as only 4 gigs in Sys Inf

[HaLo2FrEeEk]

I recently upgraded from 4 to 8 GB of RAM in my Windows Vista Ultimate x64 machine. I was happy for a while seeing 8.00 GB in System Properties for the RAM. Then I opened up system information and saw this:

Installed Physical Memory (RAM): 8.00 GB
Total Physical Memory: 4.00 GB
Available Physical Memory: 5.07 GB
Total Virtual Memory: 16.1 GB
Available Virtual Memory: 13.2 GB

Shouldn't "Total Physical Memory" read 8.00 GB as well. I thought that my computer was justso fast with the 4 GB installed that I wasn't seeing in improvement with the 8 GB, now I realize that Windows was just reporting what was physically there, not what was usable. How can I make all 8 GB show up, this really pisses me off. I know I only spent $160 on the 8 GB, but it's money I could have not spent if it's not all going to be used.

Someone please help me out with this, I don't know if it's a setting I need to change in my BIOS, or a jumper or whatever (there are very few, and I mean like, 1, jumpers on my Mobo). Anyways, can someone please tell me how I can fix this.

 

[Tmagic650]

Have you installed Vista, SP1? Is the new 4GB memory compatible with your motherboard. It is the same brand and type as the original 4GB?

 

[HaLo2FrEeEk]

I have SP1 installed, and the memory is compatible. All the modules are the same, I had 4x1GB and I took them out and put in 4x2GB.

 

[Tmagic650]

Defective motherboard?

 

[HaLo2FrEeEk]

Uhm, nom otherwise you'd think something else would not work. It's reporting that all 8 gigs of RAM are there, but that only 4 are usable, that's a wrong setting somewhere, but I couldn't find it in the BIOS setup anywhere, and I couldn't find it anywhere else. I've had this mobo for a year now and nothing's gone wrong with it.