@2625055 - Yes, I understood you, and see the issue. I explained above why you get that error (your CMD prompt is not Admin CMD Prompt), and explained how to properly get Admin CMD Prompt so you don't get the error.
If you see HPET in device manager it's not disabled I think. Please do as I mentioned above and get FPT BIOS dump so we can check. Or, maybe you can also save BIOS copy from Qflash in BIOS, I forget?
Go to Qflash, and see if there is a save or backup function, if there is save and send me to check. Or, you can make backup from DOS with EFIFlash included in stock BIOS package >> efiflash.exe backup.bin /S

Hey i just go back to that because i need how i said hpet switchable in bios for completly turn it off if u can just make me that way i will be rlly happy. Before when i got normal hpet in bios in old pc i just make it switch to off and it's no more in devices in windows. Now with ur bios it's still there. Can u modify bios for me that way i can turn it of like in a original bios in first pc?

@2625055 - Still waiting on backup from you to check, I already hard disabled HPET and this works for everyone, so something didn't flash in and we need to check what and why, and if needed flash BIOS another way.
I gave you two methods to dump current BIOS so we can check, so waiting on you for that

Here u are i make save under qflash from bios. https://easyupload.io/julb55

@2625055 - Looks good, same as BIOS I sent you (all is disabled) You probably need to disable HPET in Windows run the command if you want it removed from device manager >> bcdedit /deletevalue useplatformclock
Here is opposite - To enable HPET as the only timer run the command bcdedit /set useplatformclock true

In my testing for Gigabyte Z390, shown below change log area here, I found it's best to leave enabled for lowest timer results (see test image x4) - None of this applies to "If you can see in deceive manger" or not, I did not look at that, at all
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Can u btw unlock me that option in any bios ? for visible and switchable in bios hpet and PCH config?

@265055 - No, that's not possible in this BIOS, Well I mean not like you think of with "old PC". I can make visible for you if I spend many hours of work, but it will be same as I gave you above.
Win10 does not act like Win7 (I assume your old PC you mean, where you disable in BIOS then it's gone from device manager)

If you want it gone from device manager you can run this command (but it's better you leave default "True", otherwise timers are worse with it disabled in BIOS - that I sent you) >> bcdedit /set useplatformclock False

Good afternoon! I ask you to help unlock the HPET function in the BIOS, thank you in advance.
GIGABYTE Z390 GAMING X motherboard
BIOS is F10c

Dear Lost_N_BIOS, please, could you modify the BIOS ver. F10c for z390 gaming X to disable HPET? I am experiencing terrible micro-stuttering in games and tired of trying to resolve this problem - looks like my last hope is this thread and your help...

@Shedpwnz @zxr - I made F10c edit before and posted somewhere here, but now I can't find the thread or post
Here is previous edited BIOS from June - https://www.sendspace.com/file/3ybmtj

Merging to other same board/request thread, moving main thread to requests

Dear @Lost_N_BIOS, please, may I ask you to modify the BIOS ver. F10i for Gigabyte Z390 gaming X to disable HPET and enable "Writes to SMBus addresses 50h - 57h"?
Thank you very much for considering this request.

@Lost_N_BIOS, you are my hope for the request listed above! Please-please...

Could someone help with this request, guys?

@zxr

If no one can help you here.
I thought i can help you out to edit bios in this mainboard ,first make a bios dump with this tool and capture screenshots under Settings => IO PORT and under Settings => Miscellaneous then attach them.