I cannot connect to the internet

Firstly, what operating system are you using?
applicable for windows xp or windows 7. press Windows Key + R
select the appropriate network connection (e.g. Local Area Connection). Right click the Local Area Connection choose Properties. For windows xp, doble click Internet Protocol. For Windows 7, double click Internet protocol IPv4. choose Obtain an IP address automatically. press OK. right click again the Local area connection then choose Status. there tou can see that your computer is negotiating for an IP address from the dhcp server. if still cannot obtain an ip address, press Windows key +Run then type "services.msc". scroll down and find DHCP client. ensure that this service is running.
Please also try to check if the network you are connected does have a DHCP server.

Go through your Network Connections, and use the Wizard to make a new connection. Follow the wizard to connect to the " Internet."

Other thing to check is, On the router, do you have the WAN connected to your internet service.?

Otherwise, your connection to the router will be great, but the router will have no service to access.

You are connecting to your local network, but it doesn't sound like the router is making the connection to your Internet service provider. What sort of Internet service do you have? (ie. cable, DSL, fiber optic?)

If you connect your computer to the router with an Ethernet cable do you get the same result?

Assuming that Windows has recognized the modem, and has loaded the correct device-drivers, Windows can use the modem.

You'll need to find an Internet Service Provider that provides "dial-up" service.

You'll need to have a land-line telephone (not a cell-phone) with your local telephone-company.

Connect a 4-wire cable (not an 8-wire Ethernet cable) from the "line" port on the modem to the telephone wall-jack.

Then, follow the instructions given you by your Internet Service Provider to configure your modem to connect to their dial-up server. Or, telphone them, and their Technical Support staff will guide you through the necessary configuration steps.

may in service pack 2 there is no LAN but you have to reinstall to he your original service pack that you to contact dell and one more thing for you have to install drivers of connection or internet because your service pack2 has not installed drivers

Nine times aout of ten the company you choose for your internet service can and will help you with this. You are choosing a local provider for your service, aren't you?

I found this link that might help you...

Vista Connection Problems

Sounds like a dial out problem. Talk with your local telphone service and try getting a service call to check your line.

Its possible that you dont have the linksys router configured correctly. can you tell me what is the model no. or brand of your modem? And who is your internet service provider?

this will help us to give you the right steps on how to resolve this concern.