I cannot access an Internet in one of my computers

if you are using dynamic ip address makes sure in that computer that are not connecting has no static ip address, go to my network places and hit propertis, and select tcp ip4 and hit properties, make sure its selected as dynamic not static, if this not working this means, there is cable problem, or network card problem. or try to change the port from the router could be the router port is bad.

Good luck

On your computer having the problem, we need to determine if the connection to the router is good. To do this:

Click START > RUN, and type cmd (hit enter)

A black window should come up. (known as a command prompt)

within that window, type ipconfig and hit enter. This will give you your PCs IP address along with some other information.

If your cable is bad, you will receive a "media disconnected" message. (try another ethernet cable)

If your connection is good but your PC is unable to get an address from your router, you will have an IP address of 169.254.x.x (x = a number from 1-254) If this is the case, try resetting your router by first powering it off/back on. If that doesn't work, you may want to try a reset to default settings. (usually there is a tiny button on the back of the router you will need to push in. Check Linksys site for specific info on your router model)

If your PC is getting an IP from the router, it will be in the 192.168.x.x range. If you have an IP in this range, your router connection is probably fine.