Should have 9GB of RAM but I have 4GB

I purchased this excellent new computer within the last year I would say. Basically zero problems with it until I couldn't boot up at all. It would try to load Windows but simply fail and restart. I tried using a restore point, which I had to run from a disk because the internal one would not load. I successfully booted up twice from using a restore point. Then I eventually fixed the problem by finding that I had a loss RAM card. I simply moved this RAM card from this dis-functional RAM port to my empty port. I currently had 9GB of RAM installed. 4x2GB sticks and one 1GB stick. Then, happy as could be that I fixed my computer, I checked the RAM in my Control Panel>System view and saw that I had 9GB of RAM, lovely. But now, over the last month or so I would say, right after I fixed this problem, I started to loss RAM. One day I checked my Control Panel>System and it said 7GB. Then a few weeks later, and it had dropped to 4GB. I am still currently at 4GB and I downloaded this program called "CPUID". It reported that I currently have 9GB of RAM installed. It also showed me each of my ports (SPD), displaying each of my 4x2GB sticks and my one 1GB stick. Now I would love to know how the hell to turn these other RAM sticks on because this is stupid that Windows 7 doesn't recognize them. I updated my BIOS and within my BIOS it shows 2x2GB sticks recognized. Occasionally when I boot windows up I have 7GB or RAM and then shortly after I get a blue screen error and system crashes.
Computer Specs:
Intel Core i7 920 @2.67GHz
Windows 7 64-bit
Radeon HD 4650
HP Pavilion e9280t