Diablo® III

Hey guys, I've been trying to install diablo and i get to 41% and it stops. i read this

"Your installation folder should not have any files with the .Part extension. If it does, it indicates the downloader was closed prematurely. Restart the downloader in this case, selecting the same location the "Diablo-III-8370-enUS-Installer" folder is in, and it will check the existing files and download what's missing. It's important to let the downloader finish on it's own. It will start the "Diablo III Setup.exe" file when it's done. It can take a while so please be patient."

I checked and saw i do have a file that has the extention .part but how do i "restart the downloader?" any help is appreciated!