For EA Origin instructions see here.
Tutorial Videos
1. Introduction
The most common applications for PC Video Games are Valve's Steam and Electronic Art's (EAs) Origin. This guide goes through the backing up of their Game Installation Files onto an external hard drive which can be 10's-100's of GBs depending on the size of your game library and the subsequent reinstallation of the program and games without wasting time and bandwidth redownloading everything.
In brief we essentially copy our Games Installations Folder onto an external hard drive, reinstall the program on a new Windows Installation or transfer to a new computer and then use the program to search for the Game Installation Files and recreate the necessary links within the Windows Registry which allow you to play the games on the new Windows Installation.
I recommend a 2 TB External Hard Drive. These ones are powered solely by the USB.
USB Type C to USB 3.0 Connectors
If your computer is brand new and only has USB Type-C connectors then you may need a USB Type C to USB adaptor. I used these on my XPS 13 9365 (please use the affiliate links to help fund my guides).
2. Backing up SteamApps Installation Files
If you can access your current installation, go to your Steam Library. To the left your installed games will be shown lit up and the games which you own but have not installed will be greyed out.
It's advised to close Steam. Open up the notification tray and right click Steam and select close.
Open two instances of Windows Explorer.
In the left we will open up the Common folder which contains the Steam Games Installation Files.
This is found in:
C:\Program Files (x86)\Steam\SteamApps
If your current installation is working.
Or:
C:\Windows.old\Program Files (x86)\Steam\SteamApps
If you have reinstalled Windows without wiping the drive.
In my case I do not have a Windows.old folder.
The Common Folder:
Contains the Installation Files for all the installed Games:
You can right click the folder and select properties:
In my case the folder is 66 GB: 
Now copy the Common folder to your External HDD:
This may take a while depending on the number of games you have installed and hence the size of your common folder:
To clear things up, I will just make a new folder called Steam and move both the Steam Instructions and common folder to it:
That's your Steam Game Installation Files backed up.
3. Reinstalling Stream and Recovering Steam Game Installation Files on a New Windows Installation
On your new computer or Clean Windows Installation. Install Steam and Log in as normal. All your games will be greyed out:
Do Not Click Install on Any Game. Instead Close Steam.
Go to the notification tray and right clicking Steam and select Exit:
Go to
C:\Program Files (x86)\Steam\Steamapps
Copy your Common Folder from your External Hard Drive
Launch Steam again:
I can highlight the next game on the list that I want to install, Fallout and select Install:
Leave the default location as is and it will use the game install files present. Select next:
N.B. it will see that the folder already exists and give you the option to install the game elsewhere if you do this (Steam will redownload all the files)…
It will discover the existing files for Fallout and check their integrity as well as creating the necessary modifications to the Windows Registry so you can actually run the game:
Once done select Finish:
It will be installed and not dimmed out on the left hand side:
