uTorrent
From lurkmore wiki
μTorrent is a file transfer application for Microsoft Windows. It is still the best program to use with torrent files even though the last good version was released in 2011.
The only version worth running is μTorrent 2.2.1.25302. It's also generally the only version that is allowed on most private trackers.
μTorrent 2.2.1.25302 download (password: lurkmore)