I am struggling with this since Windows 7. Copying through the Explorer of a 1,5GB file starts at a reasonable speed, but drops down to 8MB/s after about 5 seconds. See attachment. I have a gigabit wired network existing of a PC with Realtek GBE nic, a Netgear WNDR 3700, a gigabit hub and a Windows 2012R2 server with Intel Pro nic. Copying from the server to the PC works consistently at 100MB/s. Internet speed is not affected while copying. What I tried sofar: all kind of settings on the Realtek nic. Removing hub. Replacing network cable. Resetting router. Updated Realtek drivers. Could someone please advise on how to exactly troubleshoot this behaviour step by step? Thanks.