I found this easy way to do it. (With EvoX)
Start up your xbox and wait for the blue screen to load.
Insert the game you want to backup and wait for the LED to turn solid green.
FTP in to your xbox and open the D: drive.
Make a folder on the desktop of the game you are backing up.
Highlight all of the files/folders in the D: of the xbox.
Drag and drop them to the folder you just made on the desktop.
Just wait alittle and your done.