Problem with RAMs

[BufusTurbo]

Hi folks.
Some time ago I acquired a PC with 8 GB of RAM, which ran just fine even though the hardware is not exactly new (example: it has two GTX 580 graphics card of which one never actually worked, but I digress.).
However, recently I experienced some degree of lag, fps loss and outright freezing when playing newer games like Inquisition and Fallout 4. I thought the problem was somehow overheating and I cleaned the interiors of the machine, but to no avail since there was really not much dust inside to begin with.
Thing is, yesterday I checked Ccleaner and it said the system had 4 GB of RAM instead of 8!
I checked if RAM banks were properly inserted in their connectors and they actually were, so I removed them, cleaned them with compressed air and installed them back, changing slots in case they were somehow fried.
Sh*t hit the fan when I switched the computer on, since this is what I got once Windows loaded:

 

Before that, the BIOS said the PC had the 6 GB of RAM.
I changed slots AGAIN, this time putting all banks altogether, as in all 4 banks on the 4 rear connectors.
This time BIOS said I had 8 GB of RAM, but Windows BSoD'd in a manner of seconds with the same error message as before.
My memory banks are 4 Corsair TW3X4G1333C9DHX XMS3, DDR3 1333 MHz CL9, the motherboard is a ASUS Rampage IV Extreme.

What could be the problem? Fried memory banks, dead connectors, the motherboard?

Thanks in advance.
 

[nameless701]

 

What could be the problem? Fried memory banks, dead connectors, the motherboard?

...Corsair???

 

I had the same problems with Corsair. I then changed the manufacturer and since everything runs smoothly.

 

MB: Asus Rampage IV

CPU: Core i7 3930k

Windows 7 Ultimate

 

memtest shows no errors with the corsair xms...only windows says "memory-error" (bsd)

[BufusTurbo]

I ran memtest.

Aaaaaand it found more than 60000 errors in two memory banks.

I'll just scuttle the things and take some new ones, hoping the old lady motherboard is still holding together.