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Restart the router
The router sometimes makes the Internet connection slow, unexpectedly. Other times it doesn't reconnect to a network automatically. There are lights on every router which should tell you whether the internet connection is active or not (i.e. if you can browse the Internet or not.
If you notice that the lights are not working properly, the best solution is to restart the router. The easiest way to restart the router is to unplug the power cord from the outlet and wait for a couple of minutes. After that plug it back in the outlet and everything should be fine.
If you wonder "why my internet connection is too slow" and you recently bought a new router, make sure to protect it with a password. When you buy a router and install it for the first time, the security feature is not enabled and everybody who is in your router's Wi-Fi range can connect to it and "borrow" your Internet. This is one of the causes for a slow internet connection, especially if the "borrower" uses your connection to download games, movies and etc.
All you need to do is to activate the security feature offered by the router. In order to do that you need to access your router by following the manufacturer's instructions and set a password which nobody except you and your close family won't know. Make sure to choose WPA2-PSK encryption method, because it is impossible to be decrypted.
If you live in an area where every house/flat has a router, it is possible to experience difficulties such as slow internet connection. In order to broadcast the internet connection, routers need a certain channel. There are 11 (or maybe more, depends on the router) channels which routers may use. By default routers are set to automatically choose a channel, but you can manually set the channel you like to use.
If your internet connection is too slow, changing the channel should resolve the "internet really slow" issue. Set a channel that is used by a small number of routers. Your next question might be: "How do I know which channel is less used?"
WifiInfoView is the answer to your question. Run it and after the scan is completed, see which channel is used by a very small number of routers (or no routers at all) and set it.
Access the router's user interface. Usually typing 192.168.0.1 or 192.168.0.1 in a web browser (Mozilla Firefox, Google Chrome etc.) and entering the router's username and password (default: admin/admin) will be enough. Having entered the router's user interface, click on Wireless Security (or similar name), locate the Wireless Settings (or similar) tab and change the channel (set to Automatic by default).
Note: Every router has a different user interface. Usually, the channel settings are under the Wireless settings section. But, if you have trouble finding it, consult the router's manual, or the manufacturer's website.
This helpful guide will help you find the DEFAULT router IP address, username and password.