Realtek PCI-E Ethernet (LAN) Drivers For Windows 7-11

If I remember correctly, using the Realtek setup.exe is possible, it will tell you that the install was successful; but in reality the driver is not applied, nor visible in the Device Manager 
So I have uninstalled the driver package, and resorted to the manual install method; to try and remedy the dropout issues myself with the latest non-power-saving release.

But the manual install method does not have the ability to manipulate the registry keys 
So I suspect that I might be missing something.

P.S. I presume your RTL8125B chip does not have such connection stability issues?
P.P.S. I have an ASRock board and funnily enough, in their official networking FAQ they have a tutorial how to disable EEE and power savings features for the Killer E3100G driver; but they do not improve anything...
 

You are right, I don't have problems with the stability of the connection.

Can you provide the PCI, Vendor ID and Subsystem ID and the ClassGUI?
You find these values when you right click in the device manager on the Realtek PCI card, select Properties and then Details.
In the Dropdown menu you will see the HarwareIDs and the ClassGUI.
You can copy the values by right click on them and post them here.

Cheers
Tom
 

(The following driver details are using the Realtek driver on my Killer/Intel E3100G; in Device Manager currently reported as "Realtek Gaming 2.5GbE Family Controller")

Class GUID: "{4d36e972-e325-11ce-bfc1-08002be10318}"
Hardware IDs: "PCI\VEN_10EC&DEV_3000&SUBSYS_30001849&REV_06"
 

You won't like what I am telling you now.
Realtek driver doesn't support your device, so running the setup program will install, but of course won't show up in your device manager because no matching Device ID is found, so better uninstall it.
You are stuck with the Intel Killer Performance Suite.
I uploaded the extracted driver v36.24.12162 to Mega, it contains the Windows 10 and Windows 11 driver, I suggest try both.
mega.nz/file/lQ9REbAa#_I314KbroyacvMAWDm...kc6D5S2YD-NpkEymylKY
It is possible that you messed up the registry with the wrong driver, so maybe clean up the registry which still has references to the Realtek driver.
Also, the 8125B is not supporting *IdleRestriction, so it won't show up in the registry and can't be selected in the Advanced Tab of the driver.

Cheers
Tom