This is a download manager worth trying out, it's not a freeware but you can use the trial version for free for a while if you like it, Currently I'm using the trial version and it really works but i can't honestly guarantee the 500% increase the publisher claims but it's fine by me.

Publisher's Description:
Internet Download Manager can accelerate downloads by up to 500 percent, schedule downloads, recover and resume downloads. The program features a smart download logic accelerator with dynamic file segmentation and multipart downloading technology to increase ftp, http and https downloading speed.

Latest Changes In The new Version, Internet Download Manager 5.11 Build 5:
- IDM checks and runs the installation process if necessary to re-install "IDM CC" -extension for Firefox and other Mozilla based browsers
- Fixed several bugs

Check it out at http://coolfreewareandmore..com/