Your phone opening every site on the same WiFi is the best diagnostic gift you can get: the line, the router and the internet are all proven alive. The fault is inside the PC — and it is usually one of four DNS-shaped suspects.
Treat the working phone as a witness, not a taunt. It has just cleared the router, the line and the ISP in one glance. Whatever is wrong lives inside this one PC — because every device carries its own DNS configuration, its own cache, and its own software that can tamper with both. The PC-side suspects for this exact split are few and checkable: a manual DNS entry pointing at something dead, a stale cache, entries planted in the hosts file, and leftovers from VPN or security software. Work through them in this order, testing after each one.
Run ipconfig /all on the sick PC and read the DNS Servers line. If it shows an address that is not your current router and not a known public resolver, you have likely found it: a manual entry set long ago — for an old router, a previous office, a forgotten experiment — still quietly in force.
Phones rarely carry such entries, which is why the phone sails past the fault. The repair is the IPv4 properties dialog: either replace the entry with a working pair such as 8.8.8.8 and 8.8.4.4, or choose Obtain DNS server address automatically and let the router decide again.
The router may have stumbled for ten minutes yesterday; your phone shrugged it off, but the PC cached the failures and keeps replaying them. This is the cheapest fix in the whole series, so try it early:
ipconfig /flushdns and confirm the success lineipconfig /release, then ipconfig /renewIf sites return immediately, the network was never broken today — only the PC's memory of yesterday was.
Windows keeps a small text file that can pin a name to an address manually, bypassing DNS entirely: C:\Windows\System32\drivers\etc\hosts. Legitimate entries are rare on a home PC. Old tweaks, bundled software and some malware add lines that send specific sites to wrong or dead addresses — and those sites then fail on this PC only, exactly your symptom.
If the file refuses to save or lines reappear later, something is actively maintaining them — jump to the malware check page in this series.
A VPN client that was uninstalled badly, or a security suite whose trial ended, can leave the PC pointing at a DNS server or proxy that only existed while that software ran. The phone never had the software, so the phone is fine — the split, again, is explained.
Check two places. In Settings → Network and internet → Proxy, a manual proxy you never set should be off. And in the adapter list (ncpa.cpl), disable any ghost VPN adapters left behind, then retest. If the PC was recently on an office network, also confirm its DNS is back on automatic rather than still aimed at an office server it can no longer reach.
Work the list once more, slowly — in practice one of the four is almost always responsible. As a controlled last step on a home PC, Windows Network reset (Settings → Network and internet → Advanced network settings) rebuilds all adapters and settings at once. Know its price before clicking: saved WiFi passwords and VPNs are removed.
And keep the honest alternative in view: if the PC fails the gateway ping too, this was never a DNS case — that is a WiFi adapter or driver problem, a different repair entirely.
See every step on a real Windows PC — the tests, the commands and the DNS change, in order.
▶️ Watch Full VideoAlmost certainly not. A broken card would fail to connect or fail the gateway ping. A card that connects, gets an address and answers pings is healthy — the fault sits in the settings layered on top of it, which is what this page checks.
That pattern points at a manual DNS or proxy entry set for one network and wrong for the other — typically the office server entered by hand. Set DNS and proxy back to automatic, and let each network hand the PC its own settings when it joins.
It is a valid last step, not a first one. Network reset removes saved WiFi networks, passwords and VPN configurations, so you rebuild those by hand afterwards. The four checks on this page take ten minutes and usually find a single wrong value — a far cheaper repair.