Hello! I want mod to unlock advanced menu options in my bios.
My BIOS is Aptio AMI UEFI 1.40 version.
My notebook is Toshiba Satellite C55-A-1NV x64 with PT10S motherboard, it have got a Intel Core i5-4200M CPU with a average Intel HM86 (Lynx Point) chipset, works fine. Yes, I know my notebook is very old, but I still need and use it.
My motherboard can work with other DDR3 memory modules, and I want to upgrade my memory.
I have in my notebook 1 Samsung M471B5173QH0-YK0 DDR3 1600 MHZ PC3-1280 SDRAM SO-DIMM module.
I have 2 Samsung M471b5273CH0-CH9 DDR3 1333MHZ PC3-10600 4 GB modules to upgrade my PC. In theory they can work on my PC. But if they not, please, say why, I need to know.
When I put new modules, PC turns on, but after that goes off, I looked and tried many things to make work my modules, but I believe that I need to change settings in BIOS. They are locked for me.
So, I need to flash my BIOS and create a restoring point.
I have read Modding intructions in this site, but I need help, because I don't want to brick my PC and didn't face this earlier.
I will be very glad if someone could help me. If you need more informacion, feel free to ask, I will get you all information.

Product number is PSCGNE-00300LCE
Your device supports 8gb and up
For 4gb ram and below use Windows 32bit,
For more ram (8is the sweet spot,recommended minimum) use Windows 64bit
It all comes down to memory density.and thats your problem,not bios.search results says your chips are 512x8,so you need to look for the same builds.4 on the front and 4 on the back side of the ram,there are total of 8chips.each of them are 512mb.
You can use kingston’s/crucial’s memory finder, easy way
Your bios is the latest version by the way

You have already the latest bios, did you try updating the ME? It may help fix some issues, but for sure it has security fixes. (be careful NOT to update if your laptops turns off without a warning)

In AMI bios pressing a combination of keys can unlock the hidden options, although other say it doesn't work , but it works on my laptop, you can google them, it's worth the try

In my laptop when I press right ctrl + right shift + left alt + F2 ....... just it has to be the exact left keys and right keys and in the same order or it will not work.

I understood. I have ran Crucial scanner, and see, that I have wrong memories.
It shown that I need 4GB DDR3L-1600 SODIMM.
I found the same model of my original in online shop. So, if I will put same Samsung memories, as my notebook have, it should work without problems?
Also, there is 1Rx8 and 2Rx8; 2Rx8 says that memory are on both sides, so if I am not wrong, mine is two sides, yes? So I need 2Rx8, yes?
I attached photo.

1R or 2R means number of ranks.

"While most often the number of sides used to carry RAM chips corresponded to the number of ranks, sometimes they did not. This could lead to confusion and technical issues."
https://en.wikipedia.org/wiki/Memory_rank

Thank you for the help!
I have bough memory module according to your advices, and it works with my notebook without modding BIOS.
So, this topic is closed.