Make and model of laptop? Built in wireless? You might need to re-install the wireless drivers.
Check WZC is running;
Start menu/run, type services.msc, press return, scroll down to Wireless Zero Configuration - is it started and set to Automatic? If not it may have been disabled by a third-party wireless management suite that came with your laptop/wireless device. None are simpler or more straight-forward than the built-in Windows one in my experience.
The above assumes you are using XP.