WARNING!!!! I did some experimenting with Windows 10 over the weekend and found an issue that I'm sure some people here will run into.
If you're running a VPN Client App (I had the issue with the SonicWall Global VPN Client), you must uninstall it PRIOR to the Windows 10 upgrade. Otherwise, the network adapter will stop working.
I tried uninstalling it in Windows 10 (big mistake), but it did not fix it. Rolling back to Windows 7 did restore the network adapter, but at that point, Windows 7 thought SonicWall was still installed, and nothing that I've been able to do so far has changed that (can't completely uninstall, can't reinstall, can't find anything in the registry, etc.).
I did read that Windows 10 has issues with existing VPN Clients, so I don't think it's isolated to SonicWall. I wish I read it before trying to install, but, oh well. I hope this helps someone out there. I'll post an update if/when I get it working before losing interest.