I'm on the latest Insider release, but I remember having this issue even before this build. Don't know exactly when it started. I never had it on Windows 8.1 and don't think it started immediately after installing Windows 10 a few months ago. This is on my custom built desktop Download speeds through flash seem fine (so speedtest.net shows 100mbit), But FTP and Bitorrent sync transfers from my server seem capped at 20mbit. Won't go any higher. On my macbook I get 100mbit. I tried downloading from other sites using HTTP with same results (not exactly same but slower in general) so it's not just my server. Using an OVH test file I get 3MB/s down on Windows 10 and 10MB/s on my macbook. Across the board file transfers are much slower and I don't get why. Besides flash speed tests, Steam seems unaffected. What is affected are downloads through FTP, HTTP, and bit torrent. Both devices are connected through AC wifi. I tried ethernet with same results. I tried bypassing router and going to modem. Made no difference. It's definitely not the connection because I just transferred a file between the two devices over wifi and it was going 30MB/s. It has to be something with Windows. I just don't really know how to troubleshoot this. Anyone have any idea?