Many people experienced problem in their router after their router was turned off. Upon turning on the router, the computer, and open your browser, what you've got is "Page Cannot Be Displayed" message.
What you do is you try to type again the web address (URL) . But upon trying that for several times, you tried to visit another site, and what you get is the same screen, "Page Cannot be Displayed". Oh no, you don't have internet connection!
What most people do after seeing this message is they contact their ISP (Internet Service Provider). That a great idea! But contacting ISP is not that too easy! You are on queue of thousands of people trying to reach the ISP's technical support dept.! You wait for 30 minutes, 1 hour or 2 hours. You are now losing your patient for waiting on the line and hearing those irritating background music. After waiting, you finally got the tech support agent. You burst out your feeling and you can't help yourself from getting angry. 
But what happened is, the tech supp agent hanged up. Oh, gosh! This is what you get after experiencing the problem and waiting on the phone! You are now very aggravated! You almost throw your phone and kick off your computer! I think you better try this step by step procedures first before calling your ISP. This is proven to work for DSL ISP. Try this steps and you'll find how easy it is troubleshoot your own Linksys routerwithout calling your ISP. 1. Check the cable connection. Make sure that the modem is connected to the "internet port" on the back of the router. And make sure that the PC is connected to one of the ethernet ports on the back of the linksys router. 2. If cable connections are good, turn off the PC and if it is already off, turn off the router and then the modem. Wait for 2-5 mins. Then turn on the modem and if all the lights on the modem are steady, turn on the Linksys router, after the Linksys router 3. Check if you have valid IP address. it should be 192.168.1.x. 4. If still you don't have internet, log on the router's setup page. (don't know how? go to my article "HOW TO ACCESS LINKSYS ROUTER"S SETUP PAGE) 5. Go to the SETUP page. Configure PPPoe. The format is usually "username@isp.net" . The other is just username. For example : azumi@starhub.net. And then type your password given by your ISP. 6. Select "keep Alive" option. 7. Check STATUS tab. If status says "CONNECTED", you have internet now. If the status says "DISCONNECTED", click "CONNECT". Do that twice. If Internet IP address is 192.168.1.x, Change the router's LAN IP address in the SETUP page to 192.168.x.1. Then follow step 2.
First, there s the Wireless Access Point, which lets you connect to the network without wires.There s also a built-in 4-port full-duplex 10/100 Switch to connect your wired-Ethernet devices together.Finally, the Router function ties it all together and lets your whole network share a high-speed cable or DSL Internet connection.