BitComet is a download client that can be used in the BitTorrent, HTTP, FTP protocols.  BitComet 1.07 is built with C++ and comes for free. It is small, fast and extremely powerful P2P software.
Some of the key features of BitComet includes: Previewing of Mp3, rmvb, wmv and qt files, intelligent connection optimization, intelligent disk cache that increases your hard disks service life, multi-section download that increases download speed up to 500 times, multi-mirror downloading that helps increase download speed by 300% or more, and multi-peer download among others.
You can set global or per task speed limit for downloads and schedule your downloads with bandwidth scheduler. The NAT traversal feature in BitComet lets users behind NAT to connect through UDP. In Windows XP BitComet takes care of Internet Connection Sharing and Internet Connection Firewall by automatically configuring them.
Apart from these other feature that you would expect of a download client is all available here.
BitComet is for Windows 2000/ windows XP/ windows Vista