HELP! I think I mistakenly reformatted by WD My Book to be a Bootable Drive

First of all, please excuse my ignorance.  I was going to backup my Dell Laptop today before installing the Windows 10.  When Dell Backup & Recovery came up, it suggested I created a “system restore” on CDs, Flash, or External before it would let me simply backup the data only.  I did this, but in doing it, I think I must have reformatted MY BOOK to be a bootable type disk and now my laptop doesn’t see the “E” drive.  When I plug and unplug it, it makes the sound as if it knows it’s there.  I’ve tried to use DOS to “reformat E” but the system cannot locate “E”.  So here are the questions:  (1) did I completely screw up MY BOOK?  (2) Is there anyway to make it like it was, in essence, not a bootable drive (if that’s what I did).  (3) If so, can someone PLEASE walk me through this process (considering I’m no electronic geek).  It’s a 500gb MYBOOK and I’m running Windows8.

Glory B !!!  After posting my problem, I kept digging around in the forum for answers.  Previously I hadn’t found a solution.  I stumbled across Answer #3865 which FIXED MY PROBLEM!!!  The answer was a step-by-step for us non-computer geeks!!!  Thanks to the person that wrote the Answer #3865.  You are my newest hero!!

Hello, welcome to the community.

It is nice to read that you were able to fix the issue that you had with the drive.