Internet connection not working but wireless connection works fine

I think I tried almost everything at this point, I tried resetting my modem, running anti-virus scans, malware, adware, everything mentioned here.

If anyone has any idea what is wrong with my connection, please help

My desktop (the one that can't connect) is Windows XP and the laptop, which is connecting wirelessly and working fine atm, is Windows Vista.

when did it stop working and what were you doing when it stopped if you were on it when it stopped

Wait, do you have Wireless on your home and you share it between two computer ? Or, you'r only Client, and you have Wireless IPS somewhere near you..