It doesn't appear to be the hardware that's at fault, but the application of that hardware to running Windows 7.
I'll bet you've done nothing to re-tune W-7 to take full advantage of your hardware and ram. Right?
Windows 7, like all MS OS's, comes to you at factory default, designed to run on a computer with a single core CPU, and minimal ram, ergo, it still runs much of itself from the hard drive. It's kind of like a new Corvette, with a governor in the engine so it will only run 45 miles per hour. It's SAFE, but definitely not what the buyer wants.
BSOD's, crashes, etc., tells me and should be telling you that there is an internal conflict.
Possibly: Two programs are trying to grab the same memory locations, or, the CPU is just getting Jammed up with too many programs, services and TSR's all demanding attention. Having 50 to 80 services running in the background on Win-7 is not unusual.
It's horrible, but it's common. I shut off about 40 un-needed services when I first set up a new PC with Windows 7 on it.
Then if you have a multi-core CPU, windows will use just one, by default, till you tell it otherwise.
You have lots of ram, but winders is NOT using it effectively.