A lot of people wanna download some vedios from youtube and didn't know how,also downloading big files that realy need such kind of softwares to prevent the default downloaer of your browser and it's turtle speed.
some of them use different kinds of softwares for downloading but unfortunately these softwares may include one or more problems such as errors from time to another , or just allowing you to download from other different sites except the youtube.
This programm (Internet download Manager ) is one of the best softwars in this feild,
it's free -not trial- you will use some little patches to have the full copy.
Adding to this the Firefox Addon - "I hope that not only me who use this pro" to activate this addon just drop it into some bage in the browser.
Finally you may download this wonderfull software from here
Activation Patches
FireFox Addon
Download
Download