Hi all, Not sure if this is the right place to post for a pure Windows machine, but I'm properly stumped on this one and I was hoping somebody could help! I have an old DELL OptiPlex 760 on Windows 10 that is permanently plugged into Ethernet as a seedbox/game(s) server. C2Quad Q8200, 8GB RAM, 120GB SSD/1TB HDD. The network adapter is a Gigabit Intel 82567LM-3, currently showing as driver version 22.214.171.124, dated 20/03/2015. Tried a number of other drivers too. Power management is disabled and power settings are on High Performance/no sleep. Hardware IDs are: PCI\VEN_8086&DEV_10DE&SUBSYS_027F1028&REV_02 and PCI\VEN_8086&DEV_10DE&CC_020000. Here's the issue: download speeds won't go beyond 40MB/s, through either Speedtest, FTP downloads -- anything. However the upload speed has no issues?!! No throttling from the ISP or limits. Yet as soon as I plug my 15" 2012 MacBook Pro in via Ethernet, it gets 1000/1000 speeds without a hitch?! Same with my housemate's 2011 17" and every other Mac we've had through the doors. I just don't get it. Tried manually setting Speed & Duplex from Auto Negotiation to 1.0 Gbps Full Duplex, everything else I can think of... ran it by the IT guys at work too. They haven't the foggiest. Can anybody hypothesise as to any Windows 10 settings that could be throttling downloads but not uploads? I've disabled all of the snooping tools that Microsoft have kindly bundled. Router is RT-N66U. Already changed reservable bandwidth settings in gpedit.msc. @Weaselboy, hope you don't mind me tagging you if you have any ideas? Thank you for any suggestions anybody may have! I'm completely stumped so I'm more than happy to entertain any troubleshooting you feel is necessary. Best wishes.