Internet is not working help!

Few days ago i had no problem connecting to the internet but all of a sudden i cant connect. :cry
On DHCP it says im connected and i can access DHCP. Both wired and wirelessly but i dont get any internet connection.
I have a desktop and a laptop and i can share files through local area network but i dont get any connection on both computers.
i can ping yahoo.com from the DHCP but not from CMD

i tried reseting the LAN IP,reseting router, modem and all sorts of stuff but it doesnt work.

I use XP sp2. WRT54G linksys router and dsl modem.

Help please! D:

 

Suggestions: depending on what type of modem you have you might need to bridge your modem first. Before you do that see if you can connect to the internet first with the modem connected to pc only set for dhcp. If you can connect that way then next try to bridge the modem next. Thiscauses the modem to act as a tunnel. Then attach the router and log into it thru your internet browser. Usually a address of 192.168.1.1 but might be different for linksys, don't remember. Once you are in the router setup, set it for dhcp. I'm assuming you have a dhcp account thru your ISP. That should get you going. Your windows tcp/ip settings are probably already set for automatic. Sometimes after doing this you might have to go to a command prompt and ipconfig /release and then a ipconfig/renew to assign a new dhcp address. Hope this works