Downloading Tools
If your school doesn’t allow you to access the site where the video is located (it happens with You Tube quite often) or you don’t have internet at your school/classroom, you can many times download them to your computer and then take them to school on a USB flash drive.

There are 2 options for downloading videos:
a. Install a program on your pc that will download the videos for you. Examples of those are:
Here is a video tutorial on how to use You Tube Downloader.
b. Copy the URL of your video and use Keepvid, which is a website that will create a file with your video and allow you to download it. Here is a link to step-by-step directions to using Keepvid to downloading videos, courtesy of OneStop English.

Depending on the site where your video is located, one of the options might work better than the other. Just try and see what works best for you.