I recently sent my laptop to service and I believe they changed the motherboard. Before that I could get 1000mbps, but now the connection is stuck at 100mbps as you can see in the screenshot:
The router and the cable remained the same. I tried 2 different versions of drivers, including the last one on the realtek website. I performed a clean install of the windows, the speed won't budge.
EDIT: The laptop is an ASUS GL752VW
I know that most people think it's the cable since that solved the issue in other similar questions, but I tried other cables and the problem persists and as I said, I had 1gbps connection before I sent my laptop to service with the very same cable I use now.