I just got Vista x64, it took me 2 days to install it, because it would only take 2GB of as opposed to my 8GB, so I finally got it installed. Once it was up and running I put all of my drivers and such on, shut down my comp and put the rest of my RAM in, once again I was getting freezes and constant BSOD. It runs fine now, but with only 2GB of ram, I don't know why this is happening I would appreciate some help.
Vista Ultimate x64 SP1
ASUS M3N HD/HDMI
8GB G.Skill DDR2 1066
nVidia 8800 GTS (G92) 512MB
AMD Phenom 2.5GHz
I would start with trying each stick of RAM and run Memtest (free program). It could be a bad stick for RAM.
Also try resetting your BIOS. Just take out the CMOS battery, wait 15-20 seconds and then put it back in.
It could be that your BIOS is only set to read 2 Gigs. You could also try looking in the CMOS and see if the BIOS is set to only recognize two gigs. in that case, you may be able to increase it to 8.
Have you tried two sticks instead of just one or all of them? Some boards have issues with 4 sticks of RAM installed with default RAM settings... you might need some adjustment. As the previous poster said, you may need to increase voltage or relax your timings. It's best to check the specs of your RAM and make sure it matches the manufacturer's specifications.
If the sticks of RAM are not from the same brand or have different capacities, they may have different bus speeds and voltage requirements. For example, I originally had (2) 1GB sticks of Corsair Dominator RAM in my machine. These sticks required 1.8v . When I added (2) 2GB sticks of Corsair Dominator RAM (giving me a total of 6GB system RAM), that was when I ran into problems.
Even though the bus speeds were the same, and they were from the same product line, these bigger sticks required more voltage. The 2GB sticks required 2.1v; the 1GB sticks required 1.8v. My motherboard isn't designed to deal with varying voltages in its RAM slots. Because the first required 1.8v and the 2nd pair required 2.1v, that was the cause of my BSoD. Solution? I removed the smaller capacity sticks and just stuck with the bigger ones. Eventually, I will buy 2 more sticks that are identical to the 2 currently on the board so that my board will be maxed out (to 8GB).
Before investing in different capacities of RAM, I would do the research on your motherboard to ensure that it can handle differentiating voltages within its RAM slots simultaneously. Also, I noticed motherboards have a tendency of underclocking RAM due to the improper amount of voltages. Be sure you can tweak the bus speed and voltage to the RAM to ensure proper performance. BSoD typically occurs from the RAM if the RAM is damaged due to improper amounts of voltage, so be careful when tweaking the voltage! When purchasing new RAM, be certain to always do a memory diagnostic to make sure it didn't get damaged from static electricity during storage from the manufacturer.