Inspiron 1545 Wireless problem...HELP HELP!

I have an Inspiron 1545 - Vista 64- bit operating system.  with the Dell Wireless 1515 Wireless-N Adapter. It suddenly can't even find any available wireless network. I uninstall the driver, install it again and update it also. but It's the same as before! I can't connect to internet anywhere in the campus but everyone else can and have no problem! Can anyone help me plzzzzzzzzz?!!