If your computer has both wired ethernet and Wi-Fi, plug an ethernet cable into your computer so you can download any specific drivers you may need. The wired ethernet connection is much more likely to work with the built-in drivers.
Diagnose the problem
Ubuntu includes many standard network troubleshooting tools you can access from the command line, like ping and traceroute. These tools are very useful on Windows, too, where they must be run from a Command Prompt window.
The ping command is probably the most useful. Open a terminal, type the following command, and press Enter:
ping -c 5 google.com
This command will send five ICMP echo request packets to google.com. You should see five responses. If you see zero responses, your computer can't reach google.com — this means Google.com is down or, more likely, your Internet connection isn't working at all. If you get fewer than five responses, you know that you're experiencing "packet loss," which can indicate there's a problem with Google, your router, your modem, or your Internet service provider.
The ping command can help you see what the problem is — whether you have no Internet connection at all, packet loss, or just extreme latency. Ping is also essential for diagnosing Internet connection problems in Windows.
If you're new to Ubuntu, don't want to mess with terminal commands and can get online at another location, you may want to skip the terminal and use a graphical tool instead. Ubuntu used to include this tool, but now you have to install it from the Ubuntu Software Center.
Open the Ubuntu Software Center, search for "Network Tools," install the Network Tools application, and launch it. The program provides a graphical interface for ping, traceroute, and other network diagnostic commands.
Maybe it's someone else's fault
Remember, you can't always solve every Internet connection problem on your own. The problem may be with a remote website, a switch somewhere in the route between you and that website, or your Internet service provider. Ask your neighbors if they're having problems, or you check with your ISP.
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