WD My Book 2 TB - message: The Disk is not formated. Do you want to format it?

Hello everybody here!

I have big trouble with my external 2 TB WD. I was working with it (making copy of some files) and an error appears. After i stoped the disk and started it again, there was a new message: Your disk is not formated. Do you want to format it now?

The disk is full of files i don’t want to loose. I’ve tested the disk with HDD Regenerator, and there are no any corrupted sectors on it. Can anybody tell me if i have a chance to solve the problem without formating it and loosing all my files. Thank you in advance!

What OS are you using and does the drive show in Disk Management?