Cannot connect wirelessly

Hello,
I have a Toshiba notebook that i use wirelessly. I took it out of town and used it at a hotel. When I came home and went to use it.. the icon (wireless connection computer) on the task bar has a red X through it. I clicked on it to connect...(which it always has done automatically) and it says "Windows cannot configure this wireless connection." This happened once before and after an hour of Technical Support, someone finally figured it out. My router and modem are fine...it was something I had to change in the settings...but I just can't remember what?? I am not real good technically speaking .. so any help that you could provide me would be greatly appreciated!!
Thank you so much for any help you can give!
Lynne