Thanks for your quick reply
The address of the router is : 192.168.1.1 (linksys)

How can I check Mac address filtering on the router, I looked at it but
there is no mac configuration. There is no security (wep or wap).
desktop has an ip address 192.168.1.65

I can ping laptop and dns server also ping 66.94.230.35(yahoo.com) but
when I use my browser cannot access to internet.