This is usually because your laptop is far from the Wi-Fi router. Usually bigger objects in the way, including walls and other things around your house or office that use radio frequencies mess with your Wi-Fi. If you cannot move your laptop very close to the Wi-Fi router, you can update the driver software and reset the router configuration to its factory default settings.

Here are a few troubleshooting tricks that users swear by;

1. Uninstall Wi-Fi driver in device manager
2. Uncheck the checkbox that says delete the driver
3. Now rescan hardware
4. Your Wi-Fi driver should appear again