I just thought I would share what has been the solution to the problem I've been having since downloading Windows 10.
I have an XPS 8700 with a Dell 1704 wireless adapter and ever since upgrading to Win 10 it has a very spotty connection. So spotty that I couldn't use the internet wirelessly at all. I tried all kinds of things (countless drivers, command prompt stuff, etc).
The other devices that I use work fine, it's just the Dell desktop that had an issue. Well, apparently the 1704 adapter only operates on the 2.4GHz band, and our modem/router puts out both the 2.4 and the 5GHz bands. So I went in to the router's settings and unchecked the box that allows the 5GHz aspect to broadcast SSID. Voila the wifi on this computer works. I think the adapter was getting mixed signals and didn't know how to handle it. I have no idea why the wireless worked on this computer when I had Windows 8.1.
I've never spent so much time on a problem to have the solution be unchecking a box, but whatever, I'm so happy to have the computer back. And happy to be able to stick with Windows 10, I really like it otherwise.