There are three main ways you can upgrade an Xbox 360's memory. You can add a memory card which is probably the least expensive option. Alternatively, because of a recent update, Xbox 360 users also have the option of using an USB flash drive as a memory device. Or you can be completely traditional and purchase and install Xbox 360's external hard drives. The only usable external hard drive is made by Microsoft.
Go to a store and purchase a memory card. The cards come with 256 megabytes to 512 megabytes of storage. The cards are inexpensive and will provide the storage you need for the game files that you want to save.
Plug the memory card into the front of the Xbox 360 just below the disk drive. There are two of these slots. They look like oval indents and have "memory card slot" written on them.
The Xbox 360 will handle formatting etc. This is a very simple, straightforward option for adding very small amounts of memory.
Purchase a USB flash drive. Microsoft makes Xbox 360 branded drives which are available from a store like Gamestop. A standard USB flash drive from any office store or department store will also do the trick. Make sure that it is Windows FAT32 file system format or it might not work. It also should have a minimum of 1GB storage available. USB flash drives can supply anywhere from 2 gigabytes to 32 gigabytes of memory, depending on how much you want to spend.
Make sure the latest software update has been installed to your Xbox 360 console (spring 2010 or later). If not, do so through Xbox Live.
Insert the drive into the front of your Xbox 360 in the same slot as you would a controller.
The Xbox 360 will format the drive for you when you follow the onscreen instructions that can be found by going to My Xbox, and then selecting: System Settings, memory, storage devices, and USB Storage Device in that order.
The USB Storage device is a good option if you want to save small downloadable games or add-ons as well as game files.
At the beginning of most games, you will be asked where to save the data. You just need to tell it to save to your USB Drive.
You can also purchase an Xbox 360 Hard Drive. They come in 4 sizes: 20 gigabyte, 60 gigabyte, 120 gigabyte and 250 gigabyte. These are great if you download a lot of movies, games or music.
The hard drive is located on the side of the Xbox 360. Remove the current hard drive by pressing the button on top of the hard drive and remove it by lifting from the front first. If no hard drive is currently on the console, ignore this step.
Attach the hard drive again by seating the back onto the top of the console first and pressing the rest of the hard drive down until you hear a click.
If you remove the external hard drive in the wrong order or try to force it into position when replacing it, you run the risk of damaging the drive and losing your saved data or damaging the console itself.