How to troubleshoot a Windows 10 service which does not let me stop it

Note that the DNS Client does more than just cache DNS records - it gets them in the first place, so disabling it may limit internet access.

If you still decide to disable it, do this :

• Use regedit to navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Dnscache,
• Locate the Start registry key and change its value from 2 (Automatic) to 4 (Disabled)
• Reboot.

Another method is :

• Start a Command prompt (cmd) as SYSTEM (psexec -sid cmd.exe)
• Launch services.msc from it
• The Startup type drop-down now becomes enabled.

In addition to harrymc's answer, I found this while searching for the same problem :

Deactivate :

REG add "HKLM\SYSTEM\CurrentControlSet\services\Dnscache" /v Start /t REG_DWORD /d 4 /f

Automatic mode :

REG add "HKLM\SYSTEM\CurrentControlSet\services\Dnscache" /v Start /t REG_DWORD /d 2 /f

Source : https://social.technet.microsoft.com/Forums/windows/en-US/a04284f9-cf27-4f37-82fe-31255f70625f/how-to-disable-windows-10-dns-cache-services?forum=win10itpronetworking