Disabling syncing the clock in Windows 10 not working

Solution 1:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\DateTime\Servers

As a last resort, delete the servers in the registry.

Solution 2:

If these PCs are part members of a Active Directory domain, then this is the default behavior.

The Kerberos system that is used as part of the authentication of domain accounts uses a strict "time out" system in order to prevent a "replay" attack. The idea is that the time stamps on each request/response must be within an acceptable windows of tolerance (5 minutes by default). So, to keep Kerberos working, all domain members sync their clocks with the domain controller by default.

https://technet.microsoft.com/en-us/library/cc779260%28v=ws.10%29.aspx?f=255&MSPPError=-2147217396

So, that means if you are somehow able to alter the time on your PC by more than 5 minutes, you won't be able to be authenticated on that PC via Active Directory.