The link in the answer by me came out incorrectly. Here is the correction.
My computer recently crashed and my internet speed on it went from about 15 Mbps down to 1.5 down. The odd thing is that my upload speed (2mbps) never changed.
I have the latest Windows updates, and have rebooted the computer many times.
The speed is not that bad on any of my other devices on the wireless network.