Setup Issue

i'm probably making this setup more complicated than it should be but i'm having an issue getting a wireless router connect to the internet. i'm doing this for a friend, but i had to leave early, and come back tomorrow. also, i forgot what model the router was, but it was an old linksys wireless router, and it was beefy looking.

anyways, my friend is connected to a DSL modem provided by verizon. on the back of the modem it has a:

Line In____Power Switch___USB_____Ethernet

so first i took the ethernet cable end that was connected on the back of the desktop, and plugged it onto the back of the WAN port of the router. then i took the blue cable that linksys provided, and put one end on port 1, and the other end on the back of the desktop. then i put the linksys setup disk in, and went through the steps. the first attempt of going through the whole process, i got to the point after where you get to create an SSID name, and right after that where it configures it again.

at that point, it said that setup couldn't connect to the internet. so then i decided to unplug both the DSL modem, and the router; then plugged it back in. then i restarted the computer. now going through the linksys setup again, and going through the internet configuration process at the very beginning, it's now saying that i'm not connected to the internet.

do you guys know what i'm doing wrong? i tried release, and renewing the IP address.