Cannot connect to my Belkin54g router!

Your router can be reset to effectively "reboot" it, or restored to the factory defaults to clear any erroneous settings that might have been set. Your router must be powered up for this to work.
To reset the router, press and release the reset button on the back of your router. This will reboot the router and might allow normal functioning.
If this does not fix your problem, press the reset button for at least 10 seconds. Your router should then be back to factory settings and hopefully back in your control. You must now go through the setup process to get it back to a useful state.