Upgrade windows 8.1 to windows 8 Prob and lose internet

I bought a HP ENVY Desktop Computer pre loaded with Windows 8.1. I have a retail box Version of Windows 8 Pro with which I used to upgrade my new desk to in order to download Windows 10 Pro.
The windows 8 pro wiped out the entire HP pre load and did a clean install……However I could not get on the internet. Microsoft tells me that they do not supply wifi/network drivers with any upgrade but that I would have to get those from HP. How do I do that when I cannot get on the internet? So I restored the system back to HP factory defaults (8.1)
How do I upgrade from windows 8.1 to windows 8 pro and keep the hp drivers etc.
Charter tells me the problem is with the router as I get a message saying “Ethernet doesn’t have a valid IP configuration” Is there some thing I can do to the router to get on the internet?

Sounds like you have your companies mixed up

This is WD (Western Digital) website

not HP (Hewlett-Packard) website

Talk to HP Support

Maybe I have my problem wrong? The dialog box says (Ethernet doesn’t have a valid IP Configuration)
Is this a problem with my WD Router or a problem with HP?