The Windows DNS client is poorly named. It is not a true DNS client but rather a DNS caching service. It caches records of all domain names you have visited (resolved). Overall this is a positive feature for network performance as it can greatly reduce the time it takes to begin the actual connection to a domain-named network service.

The information in here is up to date as of publishing it for Windows 10.

Why should I disable the Windows DNS Client Service?

  1. The most common reason that I encounter are by people using extremely large HOSTS files. Often to block off dangerous domains/hosts. The Windows DNS Client Service is unable to load such large files and it often results in network access breaking down completely and even system instability. I recommend that you stick to a smaller HOSTS file anyways as it is less likely to break access to common websites.
  2. Privacy: This is a huge one as the Windows DNS Client Service provides a handy list of every resolved hostname to anyone and any app with user-level access. This is a better reason to disable it.
  3. DNS Conflicts: This is a more rare issue but one that is still important to mention here. Your computer/device having it’s own DNS cache may conflict with other upstream network components (home routers, ISP, etc). They may decide to route the same hostname to different IP addresses. For this reason I disable the Windows DNS Client Service and rely on my Fresh Tomato Router (Netgear R7000) to run a DNS caching service for all of my devices. It is generally faster and safer and since it runs a DNS server alongside the caching there are generally no conflicts on my network like the ones I mentioned above. Well, at least they are less likely now…

You can view all the entries in your DNS cache by doing the following as an Administrator. If you have trouble launching these apps and commands as an Administrator then press the WinKey and just type out cmd, services.msc, regedit – You will see them listed as items and you can right-click on them and select Run as administrator

  1. Press WinKey + R and hit ENTER
  2. Type in cmd and hit ENTER
  3. Type in ipconfig /displaydns and hit ENTER

You can also flush out the DNS cache by doing the following:

  1. Press WinKey + R and hit ENTER
  2. Type in cmd and hit ENTER
  3. Type in ipconfig /flushdns and hit ENTER
  4. Type in ipconfig /displaydns and hit ENTER to confirm the flush was truly successful.

Steps to disable the Windows DNS Client Service:

  1. Press WinKey + R and hit ENTER
  2. Type in regedit and hit ENTER
  3. Browse to Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Dnscache
  4. Find the key (The type is DWORD) named Start and change it’s value from 4 to 2
  5. Restart your computer.

Addendum: I do not recommend that you disable this service unless the above issues are of a higher concern to you. The performance loss from disabling it may be noticeable for some users as it may delay overall connection times (transfer rates/latency are 100% unaffected by this, no matter what anyone tells you!). If the privacy concerns are high for you, then disabling it is still worth it but remember to make use of decent DNS servers in general.