How to remove old backups from Simple Save

What don't you understand? I asked you "How many hard drives have you got?" and you replied: "1 hard drive". Then you mention "an external backup device (hard drive)". So I conlude you have two hard drives not one as you stated!
What files are in the folder "C:\Restored Files"?
I have delved more into this and now understand that what you have is a dedicated Simple Save external hard drive! Is this the case? If so it would have been helpful if you had said so in the first place hence my reference to a crystal ball!
Can you open that device to show the folder and file structure? If so please post a screenshot here showing all of the file structure.
Hre's a guide to show you how:
Screenshots and Files - Upload and Post in Seven Forums

EDIT: For other memebrs looking at this topic. I am aware that what I refer to above as " a dedicated Simple Save external hard drive" is in fact just a normal external USB hard drive with HP's backup utility pre installed!

But I asked you to open the C:/Restored Files folder. Can you do that please and post a screenshot?
Edit: While you are doing that can you also double click on that "G" drive that shows in your last screenshot and post the folder/files strucure in that. See if there is a folder named "Restored Files"?