When Wi-Fi doesn't work, try these things first
Be patient. Diagnosing a network can be one of the most frustrating chores in the tech world. If the simple steps below don't work, we have a more detailed Wi-Fi troubleshooting guide, or you can check out some helpful Wi-Fi utilities.
When your PC (or other device) can't access your Wi-Fi network, you have to find out where the problem is--your laptop or your router. So the first thing you need to do is test the network without the laptop. Try another computer--or any device that uses Wi-Fi, such as a smartphone or tablet. If that other PC or device can access your Wi-Fi, the problem is with your laptop.
If the problem is with the PC
Once you've established that the problem is with the computer, make sure that the laptop's Wi-Fi is turned on. There's probably a little hardware switch somewhere. Find it, and switch it. Windows will tell you if you turned it off or on. If you turned it off, try turning it back on.
If that doesn't fix the problem, reboot.
That didn't fix it, either Okay, time to make sure you're connecting to the right network and using the right password. Click the Wi-Fi icon in the notification area for a list of available networks. Yours should be there, and it should say "Connected," but it probably won't.
Attempt to connect to the network, and make sure you have the right password. When typing the password, be careful about letters and numbers that look alike. It's easy to mistake the number 1 with a lowercase L or an uppercase I . And an uppercase O can be mistaken for the number 0.
A few other things you might try:
If the problem is with the network
Try rebooting the network. Unplug the modem and router, wait a minute, plug them back in, wait two minutes, and try again.
If that doesn't help, try connecting the laptop to the router via an ethernet cable. That will tell you if the problem is with the router's Wi-Fi. If it is, go into your router's settings (if you don't know how, check its documentation) and change the Wi-Fi channel.