I have attempted to install Windows 10 on my desktop computer with a GIGABYTE GA-B75M-D3H motherboard and Realtek PCIe GBE controller twice. Both time the installation program failed to recognize the drivers..even though they are the latest ones (updated this year). As a result, I have NO network/Internet connectivity. (and no ability to seek help online on that machine.) A child called it free download for android.
Fortunately, the 'restore Windows 7' feature has worked flawlessly both times. (I am typing this on the same machine ONLINE in Windows 7. I have already installed Windows 10 on two other computers in my home, and both are up and running and connected to the internet. I do NOT have any VPN installed, and my network set up is pretty 'plain Jane'. The notebook I installed W10 on was nearly seven years old, but there was no problem with networking. the other desktop computer is a 3-4 year old ASUS. Again, no trouble with the networking.
This is my 'main' computer, and I really like to get it up and running with windows 10, but I certainly can't do without networking and the Internet!
What's up/
Chuck