I participated in the 1st CBT and still has the game in my Steam library. A friend of mine just got her CBT2 key just now.
I’m wondering if I can copy or backup the game in an external hard drive so that she doesn’t have to download the game herself?
Is her internet that bad that it will take an entire week to download?
Yes that works but you need to locate the Game in C:\Program Files (x86)\Steam\steamapps\common and Verify the Files after she entered the Key and Game shows up in the Steam Library but i would suggest you that she downloads it manually to avoid errors or Problems that can occur that way.
You can use Steam’s backup and restore games system under the Steam tab on the upper left.
It worked wonders on me when I was copying my steam games from laptop to new PC 
Not that it’s bad. She’s in college and uses a broadband connection with monthly quotas and stuff.
What if i dont see TOS at back up selection?