Launching Steam Game Kills Internet

[ManMan]

Hi everyone,

I’ve run into a bizarre networking issue and am hoping for some advice. Everything works fine—streaming, browsing, downloading—until I launch a game in Steam. As soon as I start a game (e.g., Team Fortress 2, deadlock, ...), the internet on my PC stops working entirely.

Here’s what’s puzzling:

The issue doesn’t happen when I use my mobile’s 5G hotspot.
The issue doesn’t happen when I connect to the internet via an Ethernet cable.
The issue is only present when connected via Wi-Fi.

Steps I’ve Tried So Far:
Restarting my PC and modem.
Disabling the firewall.
Flushing my DNS and resetting networking settings.
Using the built-in Windows Network Troubleshooter.
Updating all drivers.
Reinstalling Steam.
Despite all this, the problem persists.
Clean reinstalling of windows

Additional Info:
Steam itself doesn’t seem to be causing the issue, as it works fine outside of games.
Other devices on my Wi-Fi network (e.g., laptops, phones) are unaffected.
The problem seems unique to this specific combination of Wi-Fi and launching games at home on my Windows 11 PC i can launch games at my friends place.
What I’m Looking For:
I’d appreciate any advice, especially if anyone has experienced similar issues. Could this be related to router settings, Wi-Fi interference, ...? Are there advanced networking tweaks I could try?

Thanks in advance for your help!

[RPG Gamer Man]

since it is on a pc, it maybe something to do with the operating system itself. What OS are you using and what version?

[rhyss]

yes

[ManMan]

Originally posted by RPG Gamer Man:

since it is on a pc, it maybe something to do with the operating system itself. What OS are you using and what version?

Thanks for the response! To clarify, I’m actually using a laptop, not a desktop PC. My operating system is Windows 11 (fully updated).

[RPG Gamer Man]

Just to point out, laptops are technically not good to play games on. You will experience everything from power issues to memory storage issues wtih games. I know this is hard to hear, but i suggest a desktop pc to play games. If you cannot do this, play only older games on your laptop.

As for the reason why your internet is not working. Make sure airport mode is not turned on, and make sure your network card firmware is updated completly. Other than that it could also be your virus scanner blocking stuff. Make sure to whitelist both steam and the games you want to play for. You may have to do this both for your virus scanner and windows defender.

I do notice you have done many of these things, and im sorry i cannot help anymore than that. You may have to go to a place to get it fixed at a professional store.