Adam,
Try using Google with "Vista x64 4 GB RAM" as keywords. It is a common
problem, especially with the 8800 GPUs. I'll give you a short summary.
First, you need to go into your BIOS setup and look for an option that
is called "Memory Hole". If this option is not enabled, the BIOS maps
the GPU and some other hardware memory addresses to just above the 2 GB
limit. That means that you will encounter problems with more than 2 GB
RAM and this BIOS option disabled. I can't tell you exactly what the
BIOS option is called, because it is called different things by
different mobo manufacturers. If you enable this option in the BIOS, the
memory locations reserved for the GPU etc. are remapped, so that Vista
can use the full 4 GB of RAM without conflicts.
Second, search the internet for the NVidia 4GB memory x64 hotfix. Here's
a typical discussion that covers your mobo:
http://forums.nvidia.com/index.php?showtopic=45109
Lastly, make sure you are running the most recent nVidia drivers. I use
the 169.13 beta driver, because I am playing Crysis and have an SLI setup.
Personally, I would take out the new 2GB of RAM, boot up Vista and make
all those changes above first. Then shut down. Boot into the BIOS setup,
check that you are showing all 4 GB RAM and the RAM timings are all
correct. Then boot into Vista and everything should work.
JB
Adam wrote:
> I have been running Vista Ultimate for 6months now with no problem. I
> ordered 2 gigs of the same exact memory I had installed on my computer to
> upgrade my computer from 2gigs to 4. I installed the new memory in the
> remaining two slots and tried to boot the computer. I enabled Memory
> Remapping on my motherboard, and it recognized all 4 gigabytes of RAM.
> However, when I try to boot, windows errors out before I see any load screen
> and I either get a message about bad checksums, invalid signatures, or that
> some system file is corrupt/missing. When I take the new RAM out it works
> fine. I tried going to msconfig, boot.ini, and setting the MAXMEM to 4096,
> but that didn't help. I tried installing Microsoft update that addressed
> Vista not installing if you had 4 gb of RAM, but that didn't work either.
>
> I tried booting from the DVD, but after Vista loaded into memory, it would
> error out as well and never get to the Vista Boot screens.
>
> My specs are:
>
> P5N-e Motherboard
> Corsair 5400c4
> Western Digital 320GB HD
> Nvidia 8800GTS
>
> Any help would be GREATLY appreciate.
>
> Thanks.
>