Download first the "Internet Download Manager 6.07". Go to this website:      
http://www.filehippo.com/download_internet_download_manager/ 

Check the automatically for files like this from now on, then click Save File.
It was Downloading.
 Then right click(on the mouse) and click open.
 Click Run.
 Click Next.
  Click Next.
  Click Next.
  Click Next.
  Click Next.
 Click Finish.
Click ok
Click Close. And it already can use for downloading.In any website that have online video like youtube, movie2k.to or etc.