I have a solution, I have already done this before
Now open a routers page, go to wireless - security and change
Network Authentication : to WPA-PSK
WPA Pre-Shared Key: _______use any key, a stronger and longer for Ex.0qXbZbsKvEtas8DmN10L and not it down somewhere don't memorize
WPA Group Rekey Interval: 0
WPA Encryption: TKIP
WEP Encryption: Disable
Now Save/Apply and reboot router
Open Control Panel
Right click properties of Local Area Connection
Now change a above Tab, I think in a last tab you will something related to Network Authentication code or set up a WPA-PSK key, I don't have remember because I am using now Windows xp and it was about 5-6 months ago. ok when u will see some thing like WPA-PSK then there you should enter the same key which you have entered in WPA Pre-Shared Key in routers page that you have noted down. after applying it you will see a Laptop has showing a WLAN connectivity. Then you can use your userid and password to connect to Internet.
A router should be in PPPOE mode then only a wireless works.
To setup a router in PPPOE mode see this link
If you gain have some problem then, you should contact me in firstname.lastname@example.org
I hope it will work...