Does the WIRED ethernet card/device show in Device Manager?

You still have the Aurora-R11 on TCP/IPv4 and AUTO, correct?

With WiFi disconnected (and Access Pont forgotten) AND WIFI DISABLED ... have you tried letting it grab an IP address from the Router's DHCP-pool? 

Hi

I think the default gateway may need attention.

@Tesla1856​

Does the WIRED ethernet card/device show in Device Manager?

--YES

You still have the Aurora-R11 on TCP/IPv4 and AUTO, correct?

--YES, auto(DHCP) IP and DNS assignment

With WiFi disconnected (and Access Pont forgotten) AND WIFI DISABLED ... have you tried letting it grab an IP address from the Router's DHCP-pool? 

--It's not getting IP

I gone through dell online diag and shows network card is OK

Reinstalled driver

At this point I'm thinking the network card which I think is part of motherboard failed.

Should a PCI-e network card work... thinking of the TP-Link 2.5GB PCIe Network Card (TX201)?

thanks

Again, be sure WiFi is turned-Off in Settings (switch slid to left) and label says OFF. IIRC, you can't use Wired if WiFi is Enabled.

Coincidentally, I just installed a TP-Link Omada (medium) stack at my residence here. Runs great. Anything non-portable is connected with real cat-5e/6 wires.

Personally, I would just use Aurora-R11's WIFI until I figured this out.  I really doubt your internal ethernet card is bad (especially if showing in Device Manager).

Have you tried just using the basic Windows drivers?

https://www.dell.com/community/en/conversations/alienware-desktops/aurora-act1250-ethernet-keep-dropping/6977ab97e153922c02dd3f31?commentId=697d75cfe153922c029df4d3

@Tesla1856​ UPDATE: Booted up PC today and had network connection but only 100mb when before 1GB. Verified with another PC which connected at 1GB to same switch.

Followed through with you supplied above link and no change.

I'll  see what tomorrow

@PA.WOODCHUCK​ ,

@Tesla1856​ UPDATE: Booted up PC today and had network connection but only 100mb when before 1GB. Verified with another PC which connected at 1GB to same switch.

 

Slow progress is better than none. Good work.

Expected (since it shows "working" in Device Manager).

This is also from my (longer) notes ... but should be irrelevant if the "heavy" driver suite is uninstalled (and just using "simple/lean" Windows provisioned drivers).

-------------------

Even after:

- Disabling Auto-Bandwidth in Killer Intelligence Center (by setting to Manual). 

- Disabled the Killer Prioritization Engine.

Still troublesome.

I've found that you can simply uninstall Intel Killer Performance Suite from Control-Panel/Programs-Features, and then reboot . I found that all the Killer/xTend Services were also properly uninstalled (but you should probably double-check for lingering Services anyway). The base ethernet Network Interface Card drivers are left in place and the NIC still works fine (actually, usually better than before as it's a leaner/simpler configuration).

Removing the Killer Control Panel or the drivers to load Microsoft provided drivers might leave the "Killer Network Service" installed and running. This is reportedly even re-installed by Windows Updates on a new installation. The solution is to stop "Killer Network Service" and set it to manual or disabled with the Services window. It can also be deleted via the Command Prompt and the "SC" command. This rogue Service can poorly affect wired ethernet as well as WiFi. 

BREAKING NEWS, but not good.
 disabled killer first-no change
removed in control panel-no change
remove device and reinstall-no change

removed killer with "online tool"-no change

I don't think there's much left other than the onboard network chip/card??

I'm also comparing setting to my R16

thinking of the TP-Link 2.5GB PCIe Network Card (TX201)?

@PA.WOODCHUCK​ ,

I don't think there's much left other than the onboard network chip/card??

thinking of the TP-Link 2.5GB PCIe Network Card (TX201)?

I still suspect it's a software and/or driver problem ... but if you can't get past it ... might as well move onto a hardware fix. 

TP-Link 2.5GB PCIe Network Card (TX201) is as good of a choice as any. It's been decades since I've purchased a dedicated NIC, but we are both happy with our other TP-Link gear, so I'm pretty sure they can also build a "working NIC". $25 to attempt to move-on with your life seems fine about now.

EDIT: I think the Internal one has to be switched off in BIOS first, before you install the PCIe NIC card.

@PA.WOODCHUCK​ 

For other users who might want to to do this upgrade =

Is this the link to the card you purchased? TP-Link 2.5GB PCIe Network Card (TX201)

Into which port did you install it?

16 or 17 both are the same PCI-e spec. Was plug&play and didn't need to run mini including CD.

Like to add this was the "ONLY" time I had an MB NIC fail in all the PC's I've owned.

@PA.WOODCHUCK​ Agreed on spec, was just curious which one you used.