We could use some more detail.

For starters are you using a router to access the internet? Is it either wireless capable or attached to your access point? What version of windows are you using?

The first thing you should do is go into your internet options, either through control panel or internet explorer on the tools menu. Then find the LAN settings, and tell it you are connecting through a LAN.

Have you gone into your internet options and told it to use your lan to access the internet?

Try the internet connection wizard (in internet explorer, tools > options > connections > setup > next > connect to the internet > next > set up connection manually > connect using a broadband..always on > next > finish

It should set your computer to use your wireless link for internet access.

If it was working previously and nothing on your system has changed then its possible someone changed your settings. Alternatively I've occasionally noticed some funny effects if you don't plug USB devices into the exact same port every time for some reason.

Where the > symbol is it means go from here to the next one. So you start by going into internet explorer, going into the tools menu, choosing options, and so on.

To be exact I think the menu choice is "internet options" where it says "options".