My PC's Wi‑Fi connection has become unreliable when downloading files. Browser downloads, GitHub files, and Microsoft Store downloads repeatedly stop or fail partway through. Retrying sometimes resumes the download, and resetting the network settings temporarily fixes the problem, but the failures return soon afterward. Other devices on the same network work normally. The PC has an i5-3570, RX 580, 16 GB of DDR3 RAM, and uses an A4Tech 802.11n USB Wi‑Fi adapter. The router is in the next room, there are no extenders, and the problem did not happen immediately after reinstalling Windows. What could be causing this, and what should I try to fix it?
1 Answer
Since every other device works normally, I’d start with the USB Wi‑Fi adapter or its driver rather than the router. Older 802.11n USB adapters can become unstable because of outdated drivers, USB power management, interference, or overheating. Download the latest driver directly from the adapter manufacturer, remove the device from Device Manager, select the option to remove its driver if offered, then reinstall it. Also try a different USB port—preferably a USB 2.0 port or a short USB extension cable that places the adapter away from the back of the PC and other electronics. In the adapter’s properties, disable “Allow the computer to turn off this device to save power.” If possible, test with another Wi‑Fi adapter or Ethernet; that will quickly confirm whether the current receiver is the culprit.

I’d also check Windows Update and the adapter’s advanced settings. Try locking it to 2.4 GHz or 5 GHz, depending on which band your router uses, and temporarily disable aggressive power-saving options. If another adapter works reliably, replacing this older receiver is probably easier than continuing to reset Windows networking.