Internet Connection sending but not receiving

Hi all,

Please help me out with this.
Recently, I got my LAN Modem replaced with a Wireless Modem...
The wi-fi is working fine as I am able to connect my laptop and phones to the wi-fi...
I am also able to connect to the internet on my Laptop using a LAN cable to the modem... The problem is that even though using the same cable my desktop is showing the connection as established but it is only sending but not receiving any packets... The desktop was working fine with the previous modem, its with this modem that I have started to face problems...
I have tried setting the IP Address Automatic Detection technique, but it hasnt worked... Please please help me out with this... I have very little understanding of how to deal with these things...