Not likely.
Clearing cmos resets the bios to what it was when the board came from the store.
You should always be able to get into the bios to make any changes that are needed.
If, for example, you had previously selected "secure boot", that would allow you to only boot with the exact hardware that was present when the OS was installed.
Selecting fast boot would only reload the last successful boot contents.
disabling causes windows to load contents one at a time which it will need to do for updates.
Before you clear cmos, look through for any settings that you might have changed.
Take a picture of what you have in case you miss something.
The idea behind clearing cmos is to get rid of problematic settings that might have been inadvertently selected.
Keep in mind that your problem here is a mechanical one, namely how to get all 4 sticks to work.
It should have no bearing on the windows you are using.
I would not be patching the registry unless you know what you are doing.
And, if I were to need to, I would first take a system restore user checkpoint so I could recover if I made a mistake.
Your cpu/mobo are capable of overclocking.
If you are overclocking, reset that first.
If you have selected xmp, reset that to use default settings.
Clearing cmos should reset all.
If all 4 sticks do not work, then:
The the ram is defective;
You have a defective motherboard;
Or you have a bent pin in the cpu socket.
Test each stick individually using memtest. Just starting memtest for a few minutes and getting NO errors will suggest that the sticks are individually ok.
Use the slot that your motherboard designates to use with only one ram stick.
Run memtest86 or memtest86+
They boot from a usb stick and do not use windows.
You can download them here:
MemTest86 is the original self booting memory testing software for x86 and ARM computers. Supporting both BIOS and UEFI, with options to boot from USB.
www.memtest86.com
Memtest86+ is an advanced, free, open-source, stand-alone memory tester for 32- and 64-bit computers (UEFI & BIOS supported)
www.memtest.org
If you can run a full pass with NO errors, your ram should be ok.
Running several more passes will sometimes uncover an issue, but it takes more time.
Probably not worth it unless you really suspect a ram issue.