HELP! Wifi hotspot not connecting

my dell laptop is refusing to connect to my at&t  hot spot. Up to yesterday it worked fine and now will not connect. I have tried every singe trouble shooting it could find. It won't even let me right click to forget about other networks bc they are all getting checked off as to connect automatically, which I think may be the problem. this is my work computer and desperately need it. On another note, its not my hotspot because that connects to my netbook and ipad.

thanks

 m