If you use Internet Download Manager, you need to pay your money for this software.
If you want to have a software similar to Internet Download Manager but free, you can use Free Download Manager
Feature;
FDM accelerates downloads by splitting files into sections and then downloading them simultaneously. As a result download speed increases up to 600%, or even more! FDM can also resume broken downloads so you needn`t start downloading from the beginning after casual interruption.
Download video from video sites, such as Youtube, Google Video, etc. The video can then be saved in native .flv format or converted to one of more popular video formats.
and More
You can download “Free Download Manager” here http://www.freedownloadmanager.org/download.htm
