Hi, I recently had a hard drive (internal) crash on my main computer. Many of the important files were frequently backed up to an external hd. I'm running Windows 10, but started out on Win 7. After replacing the main internal hd that crashed, and having the shop that installed it reload Win 10, the system is not accessing the external hd. It says it must be formatted first, but if I format it, I'm afraid of losing all the data on it. What can I do?