How to Fix Uninitialized & Unformatted HDD without Losing Data?

An unformatted HDD may be caused by improper ejection, malware and virus infection, bad sectors, physical damage, etc. You can apply the methods below to fix it without formatting. As the last resort, you can reformat the external hard drive, but you should recover data from the unformatted drive with professional data recovery software before formatting it. 

An unformatted disk is usually accompanied by error messages such as "You need to format it before you can use it, " or "The disk in drive F is not formatted. Do you want to format it now?" And when it occurs, all your files kept on the unformatted drive are not accessible. 

As you said, there are I/O errors on your external hard drive. It may be the reason for an unformatted drive. I/O device errors, short for Input/Output, are quite common. It relates to the connection between the drive and the PC, the outdated disk driver, physical or logical damages, incompatible transfer mode, and improper file system.

After analyzing, you can try the remedies below to make the unformatted HDD usable again: