  I don't have a Dell, but I am having a similar problem with a Netgear WNDR4500 v1 router and an Intel I217-V ethernet adapter. Windows 10 won't recognise the router exists over the Ethernet connection, but it does work with a wifi dongle. Adding this to assist, as I don't expect Dell to resolve my problem. :-)   Hi, Not sure how much help I can give you since I don't know what system you have and whether it's considered Win10 compatible, but here is the link to the Windows 10 driver for the Intel 1217-V ethernet cards.  ((NOTE:  The link I provided is for the 64-bit version of Windows 10.  if you have the 32-bit version installed then simply change the OS dropdown list near the top of that page )) I would also say that updating the firmware on that router would be your next step.  See if one or both of those changes help.    If not, then remove all the ethernet drivers from your system, reboot, and see if Windows 10 has any innate drivers that may work.  Or let Windows Update search for, and download, a driver.  That has the highest chance of finding a compatible driver. Hope this helps. Todd
After upgrading to Windows 10, I get a limited connection to the router.  I have tried every suggesting I have seen but no fix.  I reverted back to 8.1 and all is ok.  Drivers are all up to date as far as I can tell.  The problem seems to be related to the default gateway or lack of it.  Resetting the router does no good.  My HP labtop running windows 8.1 works fine but my Dell Inspiron only gets limited access to the router. I need some help resolving the issu.
upgraded to windows 10 and can't connect to Netgear router