I have accidentally messed up my drive

Anyone who can help, I would appreciate it.
I just got a new hard drive, which I was trying to set up. I added it to my E: Drive, but somehow hurt them both. Now, I can't access either drives (although they are read as the same) and I would like to know, is there a way for me to return my drive to its previous state without formatting it? I used testdisk, but when I did, no partitions appeared. It is just an inaccessible drive sitting there. Please help, any information would be greatly appreciated.

Just disconnect it and if windows still won`t start properly run a startup repair using your windows disc. Simply adding a drive to your system should never give you a problem. You add it and windows will install the drivers and it should open auto play to explore it. You might have to go into disk management to format it but that`s all. Can you describe exactly what you did ?

It would help if you upload a screenshot of your expanded disk management layout so we can see exactly what you've done.

Screenshots and Files - Upload and Post in Seven Forums

With a bit of luck we can then give advice that will help.