@Aukkis 

Hi,

The network card being shown as "Realtek PCIe GbE Family Controller" is normal.

Is this card plugged into a PCIe x1 slot or in a longer PCIe x4, x8 or x16 slot?

In case it's not in a PCIe x1 slot, then see if you can free up a x1 slot and then plug the Realtek GbE card into it.

According to the standard it shouldn't matter, but I for example have a PCIe network card with the Realtek 2.5GbE chip and that one just wouldn't work in a x16 slot that was still empty on the motherboard. I ended up shuffling the other PCIe cards around to make a x1 slot available for the Realtek network card.
 

  @woozle 

Hi,

I've tried x4 and x16 slots since they're the only ones that my mobo has.

I've also tried my other pc and even that didn't work (it also didn't have x1 slots).

  @Aukkis 

If you've already tested it in two different PCs and in both it doesn't work, then I doubt there will be a solution for it.

These simple network cards are usually plug and play. Windows itself should already have compatible drivers built in. Besides, on my Realtek 2.5G PCIe network card the status light(s) already come on even before the operating system is loaded. (of course provided that there is another active network device connected to its Ethernet port)

In case it's possible to return the card for a refund without much effort, then that's what I would probably do.

  @woozle 

Okay, thank you.

I'll return the card and buy a new one and hope that will work.

  @Aukkis 

I wish you good luck!

A word of caution, though. It appears that most of the PCIe Gigabit Ethernet cards sold nowadays utilize the chips from Realtek.

So, better make sure the new card can also be returned easily in case it produces the same problem.

  @woozle 

Returned the card and got a new exactly same one. It didn't work at first but I got it working now.

Way better speeds than wi-fi!

Thanks for the help.