Changing DNS on one PC repairs one PC. Changing it on the router repairs the phone, the TV, the laptop and the PC in a single move. Understanding how the setting flows through your network tells you where it belongs.
Here is the mechanic most people never see: when a device joins your network, the router hands it three things — an IP address, a gateway, and the DNS servers to use. That is why every device in the house usually ends up asking the ISP's resolver. A manual DNS setting on a PC is simply an override of that handout. So the question router or PC is really a question about scope: is one device sick, or is the whole house sick? This page explains how to change the router's setting, when the PC-level override is the smarter tool, and the stale-override trap that leaves one device broken long after the house is healed.
In the default setup shown in the panel, the PC's DNS server is the router itself. The router keeps a small relay: your PC asks the router, the router asks the ISP's resolver, the answer comes back. Alternatively, the router may hand out the ISP's resolver addresses directly. Either way, the router decides what the whole house uses, until a device overrides it.
This explains two otherwise puzzling sights: changing DNS on the router fixes devices you never touched, and a PC with a manual entry keeps failing after a router change — it was never listening to the router in the first place.
ipconfig, commonly 192.168.1.18.8.8.8 and Secondary to 8.8.4.4 (or the Cloudflare pair 1.1.1.1 and 1.0.0.1)Devices pick the change up when they renew their lease — a WiFi off-and-on toggle forces it immediately. Verify on the PC with ipconfig /all and check the DNS Servers line.
The router is not always the right place. Choose the PC-level setting when only one device has the problem — the router is serving everyone else correctly, so do not reconfigure the house for one patient. It is also the right choice when the router is not yours to administer: a landlord's router, a hostel network, or an ISP-locked box with no DNS fields.
And for pure testing, PC-level wins on speed: five minutes, one machine, instantly reversible. Prove the diagnosis on one PC first; only then decide whether the router deserves the permanent change.
The failure that survives every router fix: a PC where someone, sometime, typed DNS addresses by hand. That PC ignores the router completely. If the typed server later dies — an old router's address, a previous office's server — the PC alone stays broken while the rest of the house works, and it looks haunted.
The audit is quick. Run ipconfig /all and compare the DNS Servers line with what the router should be handing out. An unexpected address there, on a PC set to manual, is your culprit. Either correct the entry or set the adapter back to Obtain DNS server address automatically and let the router rule again.
One device sick, house healthy → change the PC. Every device sick at once → change the router, because one edit repairs all of them and future devices inherit the fix. Not your router → PC-level is your only route, and that is fine.
Whichever you choose, change one place at a time and test before changing the second. Stacking a manual PC entry on top of a fresh router change makes the next diagnosis twice as hard, because nobody can tell which setting is doing the work.
See every step on a real Windows PC — the tests, the commands and the DNS change, in order.
▶️ Watch Full VideoUse the exact Default Gateway address from ipconfig, typed into the browser's address bar — not a search box. If the page still refuses, the router may only allow admin access from a wired connection, or its admin interface may be disabled. In that case, use the PC-level DNS change, which needs no router access at all.
Some ISP-supplied routers do hide or lock the WAN DNS fields. You still have two options: ask the ISP to change it, or override DNS on your own devices — the PC-level method works regardless of what the router allows, which is exactly why it exists.
It will not change your line speed. It changes which resolver answers name lookups for the whole house. If the old resolver was failing or sluggish, pages will start loading reliably again — a repair, not an upgrade, and worth being honest about the difference.