I upgraded my win 7 Ultimate to Win 10 prof.( I made a disk) Everything went smoothly until I noticed that I had a yellow triangle on the network icon. I did the windows network diagnostics and it came up with "local area connection doesn't have a valid IP configuration". I went into local area connection properties, networking under "Internet protocol version 4" and hit properties and nothing happened. I rebooted and tried again still nothing happened. I finally restored back to Win 7 but I had the same problem. I restored to a earlier date in safe mode and same problem. After a few hours I came back to try again and the problem was fixed. I want to try to upgrade again, any suggestions?
Check the SPECS on you LAN hardware, get the model of your hardware, then go to either your MFG of the PC or hardware and see if there's a win 10 driver, the driver might have installed but might not have worked. P.S. Did you restart you modem after you installed, sounds more like the hardware didn't pickup the IP again. Try this, and router if you have one off the Modem. If you still get the same problem, and you restart, then look at the driver.
Probably just a Ethernet cable going bad, or you can try resetting modem by unplugging it for 30 seconds and plugging it back in.