Recently, my Internet Service Provider or modem was not working properly. I tried restarting my computer, cable modem, and router. After a while, my modem is back online, but my router needs to be restarted. After I restarted my router, I got my internet connection back.
You restart your modem, router, switch and hub by unplugging it, and plugging it back in.
You enter the command prompt by going to the start menu> run type CMD.exe in the textbox.
You can also open the command prompt and type  ipconfig /release press enter then type  ipconfig /renew press enter.
You should have a new DHCP IP address now. If you do not, make sure DHCP is running on your router, and Windows services.
If you notice you can’t use your web browser, but you are connected to the internet, your DNS server might be down.
In Command prompt type Ping  127.0.0.1 if you can ping it, it means DNS is down. You can also try to ping IP addresses of websites like Google which is 74.125.43.104 , but it could change since IP addresses are not permanent.
It is also worth checking your network card, cables, modem, and router for damage by trying a known good piece of hardware to see if it fixes the problem.