Deleting duplicate photographs

[cruiser2]

I have somehow managed to duplicate/ triplicate most of images which are in "Pictures" on my computer. There are now over four thousand images. I am slowly deleting them one at a time.
Is there a quick and easy way to do this?
If I could only do 50 at once it would be much quicker.
I have an external HD on which I can save the images before I delete them.
Any help much appreciated.

[Workingman]

Cruiser,

Copy and Paste your "Pictures" folder to the external HD so that you have a copy of everything - belt and braces. To do this right click on the Pictures folder on your computer and from the meu pick Copy then right click on the external HD and from the menu pick Paste.

Go back to the original Pictures folder and open it so that you can see all the images in there. Right click in a blank space and from the menu choose New>>> Folder and re-name it to Originals. Drag and drop one of the copies of each image you wish to keep to the newly created Originals folder - you can choose multiple images by holding down the Ctrl key and highlighting them. Once you have all the originals in place in the Originals folder you can go back to your Pictures folder and delete everything that is left.

To do this press Ctrl and A then right click on a highlighted image and from the menu choose Delete.

[cruiser2]

Will try it later today and let you know what happens