If you're having problems with your internet connection, here are a few troubleshooting tips to help you fix your problem. The following steps will fix, or at least help you diagnose most of the internet connectivity issues out there.
First, turn off all of your machines, including the computers, routers, and modems. Make sure you unplug your modem and router. Leave everything alone for a full minute. Take your modem, and turn it on and off, which will clear up some of the data held in the modem. Make sure it is not plugged in yet while you do this.
Then, plug in your modem to a power source and turn it on. Once the lights on the modem stabilizes, plug in your router and wait for the router lights to stabilize also.
At this point, turn on one computer. If this computer has no problem connecting to the internet, turn on another computer and check its connectivity. Do this one at a time, until you find the computer that is not connecting. If all computers are online, your connectivity issues are for the most part solved. If you find a computer that does not connect or creates problems with the internet connection, the problem is not the internet network, but rather that computer. If it affects the whole network when connected, it is highly likely that that particular computer has contracted a virus.
If the first computer you turned on does not connect to the internet, take out the router and try to connect directly with the modem. It is possible that there is a problem with the router. If the computer still does not connect to the internet, you have eliminated your computers and your router as the problem. The problem can now be narrowed down to your modem, wiring, or service provider.
If the above steps do not work, try resetting your modem and repeating the process above. Do not press the reset button on your modem unless you are absolutely sure you want to reset it. Reseting your modem will clear out all your data and you will need to input your information all over again.