While Wi-Fi is a useful and reliable technology for the most part, you may face three situations that present problems: a connection error, a drop in reception level or authentication errors on the screen.
While Windows connects automatically to a wireless network in your vicinity, manual configuration may be required to connect when there are multiple networks. Click on the wireless network icon on the system tray on the lower right of the screen, and select the network to which you want to connect.
The signal strength slows down as you move away from the supply router, and eventually the connection will be lost. If too many people are connected and downloading large files, this can result in the same problem. Enabling security to restrict access may solve this issue.
An unavailable network is usually the result of an IP conflict. If two or more computers have been assigned similar IP addresses, you cannot access the network. The solution usually is to reboot the router and your system to obtain new IP addresses. Ensure also that Wi-Fi is enabled on your laptop and router.