if you did that correct and it did not work you probably have a faulty motherboard. So I don't think you gonna solve this before buying a new motherboard, testing another motherboard. If you want the same motherboard they are pretty cheap used on eBay:
https://www.ebay.com/itm/Dell-XPS-8...h=item4b4b5a85cc:g:fOUAAOSw51JbapO3:rk:4:pf:0

 

Last edited: Dec 26, 2018

thank you too much for your help.

 

hope you solve it. My advice is not to buy a old used motherboard, but rather buy a new old motherboard that fits your cpu, ram and graphic card (DDR4 motherboard does not support DDR3 memory). Buying the same motherboard used can result in headaches since that error can be something that happens on "all" those Dell motherboards

 

Last edited: Dec 26, 2018

thank you for everything, i will try to find for it solution.

 

@MIDO I agree with Pirate: try to proceed gradually.
Maybe testing your ram first in another computer (a local store around ?) before anything more.
When things drive us crazy we make crazy mistakes (I speak for myself, but I'm not the only one as Lennon said)

 

This only happened after using the iobit software. Makes me think it is a software issue, not a hardware issue. Do you have another drive you can install a fresh Windows on and see if you still have the same results? Or, a flash drive that you could put a live distro of Linux on and check that way?

The BIOS thing though, that is weird.

I'd still check it in a fresh Windows install if you haven't already

 

Can you run CPU-Z and in the SPD tab, can you post screenshots of each slot? I only see slot 1 that you posted. Or do they all match?
______________________________________
Also, what is your motherboard make and model?

Step 1: Open Command Prompt, Open Run Window and type cmd and Press Enter or Press Windows Key + X and then select Command Prompt.

Step 2: In the Command Prompt Window, type the below command or copy – paste and hit Enter.

wmic baseboard get product,Manufacturer,version,serialnumber,Model,Name

Step 3: It will display the motherboard information.
_______________________________________

Does your motherboard have onboard graphics? There may be an option that is allocating RAM to your onboard video in the BIOS. Or just disable it.

Names such as “Onboard Video Memory” or “VGA RAM Size” are common
________________________________________

Reading your OP again, it sounds like it was working and then you ran Advanced System Care and it messed up. if that is the case, you probably need to reformat or try System Restore to before you ran that program or run a repair operation using the Windows installation disc.

Advanced System Care should have asked you to create a System Restore point or backup the registry before you ran the optimizations or whatever. http://blog.iobit.com/restore-center_549.html

 

Last edited: Dec 27, 2018

i try to find place where i can check .

 

i already did that before nothing change, i put another hard disk where i install on it another windows and its the same thing nothing change

 

Thanks for the screenshots (don't see anything wrong), but what about the other stuff I mentioned?

I found someone else who had the same issue using the same RAM that you have here, and Dell basically said it isn't compatible...
https://www.dell.com/community/Desk...Mhz-installed-but-BIOS-only-sees/td-p/4228585

 

Last edited: Dec 28, 2018

how it isn't compatible and it was working in my pc for long time !!!
you mean to restore, it will not change anything cause i already change the hard disk with another OS and nothing happen and what it will change also if bios see that there is only 8gb of ram!

 

Did you update the BIOS of the motherboard and then you had this problem? What version of the BIOS do you have flashed currently?

Try updating your chipset drivers.
_______________________________________________________________________
https://www.dell.com/community/Desk...S-8500-i7-3770-Win7-Professional/td-p/4302344
"2-30-2013 03:11 PM
RE: Only 16 of 32 GB recognized - XPS 8500, i7-3770, Win7 Professional...

Is this something new or has it always been this way?

Do you by chance have Nanya brand RAM in this system? Dell had issues with Nanya RAM compatibility a while back. If you have Nanya and the system is under warranty, contact Dell Tech Support and request replacement with some other brand.

And/or, if the other "identical" system has a different brand of RAM, try swapping it and see if this system will see all of that RAM, and now the other one only sees half."

Could be an incompatibility in the RAM modules when both memory banks are filled, eg all 4 sticks installed. Or it could be a motherboard memory controller problem when both banks are filled...
____________________________________________________________________________

I see lots of people who have this problem, specifically with XPS 8500, so it may have been working, but something on the motherboard is failing when you insert all 4 sticks. I think your only option to rule out the RAM is to buy another kit, of a different brand (Crucial would be best), test it to see if the same thing happens, and then return it if needed.

If the new kit does the same thing, it must be the motherboard or some hardware issue that triggers when all four slots are filled.
____________________________________________________________________________
https://www.dell.com/community/Desk...izes-6-of-12-Gb-installed/td-p/5073017/page/3
Seems that updating to BIOS vA12 caused this issue for someone else. It's risky, but you could try downgrading to A10 or something, to see if that fixes it.

 

Last edited: Dec 28, 2018

My last advice on this thread is this: try to obtain 2x8gb modules that are recommended by the manufacturer to be fully compatible with your Dell. Install them and more likely than not you will see 16Gb.

 

"Dell forum folks inquired if I had Nanya RAM and that they've had some "bad" RAM in the last year+. They believe that this may be the culprit."

"Sounds like it could be the memory controller on the CPU."

You may need to buy a new kit to test, or a new motherboard to rule out your Nanya RAM, if you don't have another system to test.

 

i didnt update the bios this probleam happen and than i update cause i saw some comment they say on it to update the bios after i update nothing happen and even i make forcing bios flash to the A11 nothing change
the current bios is Version A14
what i have now that my rams showing as 8gb not 16gb is something new before it was working as 16gb,
i want know where is the problem first cause to decide what to do, but now i don't have where i can check rams so i will go to fixing shop or something like that to check and to know what the problem
my warranty is expired (((

 

thank you for your help.

 

i think if this the problem it mean that i must change this Memory Controller Hub or buy new motherboard and this bad news (((
any way thank you too much for your help.