Explorer crashes with added memory

Hi all, I have a rather strange problem that hopefully someone can help me with.
My motherboard Asus P8Z77-V LX can handle up to 32 GB of DDR3 1600mhz.
I did do a "memtest" on all of my 16GB DDR3 1600mhz, 10 passes, 10 hours and no errors. I had my original 4 GB still in the computer as I had to remove the other ram to install Windows 7. Once windows was installed I ran it with just the 4 GB for a few days to make sure everything was working which it was. So I then re-installed the remaining 12 GB of ram and then right away windows explorer kept crashing. I removed the 12GB I just put in and reinstalled each stick separately with the original 4 GB so each time there was 8 GB of ram installed with no problems at all.
So what gives ???
Is there a default setting somewhere that is limiting my memory???
Thanks

It could be your RAM is mixed and matched and therefore not compatible. How did you buy the remaining 12 GB?

It may also be your BIOS settings cannot support the 16 GB.


Download and install CPU-Z and Upload screenshots of the CPU, Mainboard, Memory, and SPD tabs. In the SPD tab, upload an image of each slot.

Also, go into your BIOS and post all Voltages (CPU, RAM, NB, IMC, etc.) and all RAM settings (timings, frequency, etc.)

Thanks to Dave76 for help learning RAM Stability

I will do as you stated but I also wanted to mention that when any ram higher then 8 GB is added = 12 gb (A1,B1,A2) explorer does not crash but my monitor LCD Syncmaster 932BF fizzles (like electrical interference) every now and then or the entire screen blinks. Only when the 3rd stick of 4 gb ram is used. When I add the 4th stick of 4GB ram that is when explorer crashes constantly. If I just use the 8GB memory (A1,B1) everything is fine.
This is a new computer (custom) that I had done for me. Everything is new so I am assuming they would have given me all the same make of ram. Each stick of Ram has a memory heat spacer on it which I will have to remove to see the make of the ram. My monitor is set at 60 hertz.
Also my board is supposed to be able to handle 32 GB of ram so that is not a problem.

Here is all of the screenshots from CPU-Z, I am presently running with 3 sticks of 4 GB DDR3 1600 mhz PC12800 with the odd monitor screen flicker (quite annoying). Yes all of the connections are tight. It only happens when the 3rd stick of ram is added.

With 3 modules, there may be a problem with the dual mode running. Strange that you get that behavior, though.

Also, you only uploaded one of the slots in the SPD tab. All four would help determine any possible incompatibilities between the modules themselves.

Yes I did not want to add the 4th stick with explorer always crashing when I do but if you want me to and then try to take CPU-z screenshots let me know. Here are the rest of the SPD's. Here is the info you requested from the BIOS which is supposed to be able to support 32 GB of memory. I did not find any "NB" OR "IMC" etc but here is the CPU and RAM stuff. But first I do not understand why in SPD it has my ram listed as 800 mhz when each stick should be 1600 mhz ??
BIOS
CPU fixed frequency = 250
CPU voltage = 1.080
3.3v = 3.360
5v = 4.96
12 v = 12.096
CPU speed = 3400 mhz
CPU ratio range = 16 - 34
CPU current ratio = 34
Processor cores = 4
MEMORY
Total = 12288 DDR3
Frequency = 1600 mhz
DRAM volt = 1.650
TIMINGS
All set to "AUTO"
PRIMARY CHA CHB
cas# latency 11 11
ras# to cas# delay 11 11
ras# pre time 11 11
ras# act time 28 28
command mode 2 2
SECONDARY
ras# to ras# delay 5 5
ref cycle time 128 128
refresh interval 6240 6240
write recovery time 12 12
read to pre time 6 6
four act win time 24 24
write to read delay 6 6
cke minimum pulse width 4 4
cas# write latency 8 8
RTL (cha) CHA DO 41 CHA D1 41
RTL (chb) CHB DO 41 CHB D1 32
IO -L (cha) CHA DO 2 CHA D1 1
IO - L (chb) CHB D0 1 CHB D1 0
THIRD TIMINGS
twrdr (dd) 1 1
trwdr (dd) 3 3
trwsr 3 3
trr (dd) 3 3
trr (dr) 1 1
trrsr 4 4
tww (dd) 3 3
tww (dr) 3 3
twwsr 4 4

The only thing that looks different to the untrained eye is RTL CHB, IO-L CHA and CHB (above)

could it be I need to upgrade my Motherboard drivers ?? I checked and there is more recent drivers out there but was told not to do this unless it is absolutely necessary.

It appears that slots 1 and 3 are the same, but slot 2 has a different module. That may be part of the conflict you see. It is best to get your kits at the exact same time and get the exact same model, timings, and voltage RAM kits.


Which drivers are available for update?

OK I would need to find out how to remove a memory heat spreader from my ram as each one has one of these coolers on it and they are hard to remove in order to see the type of ram and if any are different. You must be right though as before reading this I had removed the 3rd stick (A2) (nothing in B2) and replaced it with the last stick I was not using. Since then I have had no problems what so ever. So I am presently running 4GB sticks in the following A1, B1, A2
B2 has nothing. Monitor is fine and explorer is fine.
As for the MB driver update, these are the following that "Driver Genius 11" suggests I update
All Intel Chipset drivers
-2nd gen intel core processor DRAM controller
-SATA AHCI controller
-chipset LPC contoller
-USB enhanced host controller
-SMBus host controller
-PCI express

here are the new screenshots with the "different" ram removed and the last stick installed. These seem to be exactly the same.