Help! External Drive Became RAW!

Hi! There! I have a problem. I used the external drive of my friend to watch a movie on my laptop. It worked well. However, when my friend got it back, it didn’t work on his computer. And the computer message says his external hard drive need toformat. He also has a lot of stuff on the drive. So I come here to ask you for help. Is there another way instead of formatting? Now the drive is RAW and cannot work on my laptop, too. Any suggestion could be appreciated.