Hey everyone, I need some advice. I recently built my first PC, upgrading an inherited machine from my dad. I updated several components, including a new Wi-Fi card, and everything boots fine. However, I'm facing a frustrating issue with the Ethernet connection—it keeps dropping. This started during the Windows 11 installation, where the Ethernet constantly disconnected, making it hard to complete the setup. After installation, the Wi-Fi seems stable, but the wired connection is unreliable. The PC can initially connect to the network and even performs basic tests like pinging my NAS or Google, but any file transfer from the NAS causes the connection to drop after transferring 100-200 MB. When the drop happens, the PC disappears from the router's client list, but the Wi-Fi continues to work. I've tried different Ethernet cables, switched ports on my router, and even used a USB 3.0 to Ethernet adapter without any improvements. The onboard Ethernet adapter appears functional in Device Manager, and I've updated the drivers and BIOS. I'm stuck not knowing if this is a hardware or software issue. Could anyone offer some suggestions on what I might test next? Thanks!
1 Answer
You might want to try another Ethernet cable, just to rule out any damage. If the cable you're using isn’t going directly to the router, check any adapters or wall plates because they could also be faulty. I had a similar issue where a cable that seemed fine was actually causing connectivity problems. Replacing it solved everything for me.

I've checked everything on my end too. The PC goes through a switch, and I’ve tried different cables and ports, but everything else connected works perfectly. Just can't figure out what's wrong.