Slow torrents with Windows 7

After getting windows 7 I noticed that my downloads of the Linux kernel through utorrent were running at incredibly slow speeds.

Though the reasons behind this may be complicated, the solution turned out to be rather simple.

The first solution is direct, and very simple. You need to disable UPnP port mapping in the settings of utorrent, and run it in compatibility mode for Windows XP SP2. For the uninitiated: right click properties of utorrent shortcut, head to compatibility, and make it look like the picture.

Now the second, optional, part will require patching of your tcpip.sys. As you may, or may not, be aware Microsoft introduced a half-open connection limit in XP SP2, and included it in Vista and Win7. As far as the official reason, it was done to hinder the speed at which certain trojans and viruses spread. The real result: slower torrent speeds.

This is very simple. Head over to http://half-open.com/home_en.htm and grab the Half-open limit fix 4.0. Patch it to whatever you need, and restart.

You may also unlock utorrent’s max connections; head over to preferences, Advanced, and find the string net.max_halfopen and increase the numerical value.