Some reasons for poor Wi-Fi connectivity include distance, construction or physical factors, and interference from other Wi-Fi networks. Checking for these potential problems can help improve a weak Wi-Fi signal.
The further away a router or wireless access point is to the device trying to pick up the signal, the weaker the signal becomes. If the Wi-Fi connection is not working, try moving closer to the source of the signal. If the problem occurs at home, additional wireless routers may be useful.
Physical factors such as thick walls and certain construction materials can also block a Wi-Fi signal. Try repositioning the router in different areas to improve connectivity.
Other Wi-Fi networks operating on the same frequency can also cause a weak signal. Try changing the router to different channels to find one that is less crowded.