bit depth - Why are my 14-bit RAW files being saved as 8-bit on my computer?

I shoot a Canon 5D Mark ii at the highest quality setting. RAW files on this camera are supposed to be 14 bit, but when I save them on my computer, they are all being converted somehow to 8 bit. I use a kingston card reader. I'm simply copying the images into a file without altering anything. What's going on? How can I save the files at the higher quality that the camera is supposed to be recording them?