Free Download Manager Will always keep your downloads saved even after a 
computer shut down and it can continue the download from right where you left
it. You an download free download manager here: 

https://www.freedownloadmanager.org/

DISCLAIMER: I am not the free download manager programmer or something,
I am just a user who got really impressed by the acceleration and performance
of this download manager and wanted to share my impression with any random user.