Bad Internet/LAN - Please Help If You Can

I’ve been trying for weeks to get a working installation of Windows 10 on my PC, but it seems whatever I try, there’s always a serious internet/LAN issue.

Hardware as follows:
Asus P8Z68-V Pro
Intel i7 2600k
16Gb DDR3 RAM
nVidia GTX970
Current OS: Windows 7 Pro (x64)

Whether I install Windows 10 by upgrading, or running a clean installation, the problem remains the same…. Although no errors show in the Device Manager after installation, the PC is always left with a constantly disconnecting and reconnecting network/internet. After searching Google and YouTube, it seems this is a common issue, but none of the ‘fixes’ found online work for meL

I’ve tried adding a separate PCIe NIC card, which DOES stay connected, but only reaches a fraction of its listed download speed (although upload speeds seem normal).

We have another system in the house, with almost identical hardware specs, only a lower variant of the same Asus motherboard, and this works just fine!

Please can anyone help me with this? I'm disabled and depend heavily (too heavily it seems) on my PC.
I’m pulling my hair out with this!!!

WiFi or Ethernet? Have you checked the cables and connections between the computer and the router?

Its Ethernet, hence the "separate PCIe NIC card" I've tried swapping the cables over with the functioning system to no avail.

NavyLCDR said:

WiFi or Ethernet? Have you checked the cables and connections between the computer and the router?

Please try download these drivers, http://www.station-drivers.com/index...html=1&lang=fr install and try.

Is the cable connecting the computer directly to the router?

yes

NavyLCDR said:

Is the cable connecting the computer directly to the router?

I would watch the link lights on the router and/or computer to see if they turn on and off with the connection/disconnection. Then, as ZyKLon mentioned try a driver from the manufacturer, but I cannot vouch for the authenticity of station-drivers.com

Yes, i've watched and tested the router thoroughly. The disconnection is DEFINATELY at the PC. I'm just finishing some tests with other PC, then will restore windows10 yet again with Acronis, and try that driver.

NavyLCDR said:

I would watch the link lights on the router and/or computer to see if they turn on and off with the connection/disconnection. Then, as ZyKLon mentioned try a driver from the manufacturer, but I cannot vouch for the authenticity of station-drivers.com

I wonder if it's an issue with dead gateway detection. Try disabling it, reboot and test

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
DWORD : EnableDeadGWDetect 0

Well, that's a bizarre result.... It 'appears' to fix the disconnecting issue, but also DRAMATICALLY reduces bandwidth. I loose about 3/4 of my download speed with this driver.
This is driving me nuts:-(

ZyKLon said:

Please try download these drivers, http://www.station-drivers.com/index...html=1&lang=fr install and try.