The very first thing to do is try to do a so called 'release/renew' which will renew your connection with the gateway.
The following list will show you how to do so.
- Go to Start -> All Programs -> Accessories -> Command Prompt
(Vista users will have to right click "Command Prompt" and run it as administrator)
- A black box will appear. Type in: ipconfig /release
- After it is done releasing. Type in: ipconfig /renew
- This should renew your connection with your gateway.
If the 'release/renew' steps above don't fix the problem, then you can try something that is referred to as 'Power Cycling' your modem.
To do this do the following:
- Turn off all computers connected to the router
- Unplug the power cord from the back of the modem and the router
- Wait at least 5 minutes
- Plug in the power cord into the Modem and wait at least one minute for it to initialize
- Plug in the power cord into the Router and again wait at least one minute for it to initialize.
- Power on one computer and try to connect to the Internet with it.
- If the one computer can connect to the Internet, then you can start turning on the other computers one-by-one and checking their Internet connection.
If these 2 simple steps won't work, then there might be something more going on.
In this case you can post on the forums and can request detailed help.