|Advise you to connect computer directly to DSL modem, this will test whether there is problem on Internet connection. |
If it works, probably there is configuration problem on wireless router, you should log on to wireless router configuration page and recheck the configuration again. If you need more helps, this is an example of wireless router configuration, feel free to take a look.
After that, check out this wireless adapter configuration to connect to wireless network.
Hope this helps.