Back up your Steam Games
Hey, a friend of mine came up with this so credit to him for telling me about it. So you can buy games off steam but you do not want to always download it over and over again in order to play it?
Well, it is possible, All you really need to do is backup your game once you have it installed for the first time. The game can be stored on an external hard drive as well as medium such as a DVD or a CD.
Backing up the files:
Start by Opening Steam and Right Click the game you want to backup.

And go to “Backup Game Files…”, Once you click this a new window will appear.

This allows you to add more installed games to the list if you like to but today we will only do one. Now when you click next you will need tot tell where you are going to save your files.

Last but not least, when we click next again we will be able to choose the name of the file and how big the files need to be when they are split up into pieces. Too big pieces will cause trouble on hard drives so i suggest not going over 4.7 GB (DVD).

I choose DVD most of the times because it allows me to not have too many parts.
Once chosen simply click “Next” and wait until it is done.
Now if you want to you can even delete the game you want to.
All you have to do to get it fully back is Double click the file steambackup.exe where you backed up your game.
And if you pick DVD you can simply burn it to a DVD and install it from there. Though i have not tried this so do not take my word for it. I do have tried and put it onto my external Hard Drive.