Internet Connection

I use my windows laptop at my business and at home, and I have Comcast at both places. Recently, when I was at the house, I could not get out to the net. I am connecting to the XFi, but no internet. I didn’t change any settings. That has been a couple of weeks now, & I still can’t get it to connect. I have went through all of the Windows troubleshooting,
to no avail. My other devices are working fine. Any ideas?