reconfigure your wireless router... connect through wired connection and set it back up. possible someone messed your sh!t up. i doubt your using static IP at home - so i would think it is a configuration setting. can you even see the wireless connection?

to reset if needed: if you have cable internet just hold the button in for about 30 sec on the router and reset it back to oem settings - if you got dsl make sure you got your login info and set back up your pppoe