Unusual Problems after RAM change (could be unrelated to the RAM change)

So recently, I upgraded my RAM capacity to 8GB from 4GB (the RAM frequency was the same) as I was experiencing lag while using many programs. First day went without a hitch, everything ran fine and smoothly. Next day, programs are randomly crashing left and right with no apparent cause and pretty soon I get a BSOD for memory management (error 0x1A). So I figure one of the sticks might be defective, I take them out, put my old RAM back in and everything works fine. I put the new RAM in again, everything stills works fine. I was puzzled but I wasn't about to question my luck. Next day the real problems start. I can't even google my problems properly without my browser crashing (and no I wasn't using IE) and a while after booting up my PC each time I get a BSOD. At first it's just memory management BSODs like last time, but then I get a PFN_LIST_CORRUPT BSOD (error 0x4E). At this point I figured a malfunctioning driver is the cause or my hard drive has been wrecked for whatever reason (it's 3 years old so wouldn't surprise me). I decide to format my hard drive and reinstall Windows. I open up my user account to back up some data and my display is weird to say the least. Just lines and lines of colors in a repeating pattern. At this point I'm convinced the GPU driver screwed up somehow, so I try to reinstall Windows (Windows 7 Home Premium 64x). Surprise surprise, problems. At about 48% of the installation I get this error 0x80070017. As a last attempt to find a solution I try again with my old RAM sticks, same thing. I took it to the technical department of the store I bought it from and they couldn't figure out the root cause, apparently installing Windows went fine for them and they had no problems afterwards. They gave it back with only 1 of the two new 4GB RAM sticks in it and it was running fine, so I figured I'd try to put the other one back in. I did and it's started to show signs of the same thing it did a few days ago (rare but more frequent than usual crashes of programs). I've checked my CPU and Motherboard's specs and I'm not exceeding RAM capacity or frequency limits. I would appreciate any help with this matter. Technical specs below.

Motherboard: Foxconn H55XMV
CPU: Intel Core i5 760
RAM: Corsair XMS3 DDR3 4GB 1333MHz (2 sticks)

I'll provide any additional technical specs necessary. I don't know if it's related, but I'd also like to note that the RAM sticks are supposed to run on 1.5V by default but my BIOS says they're at 1.66V.