Files gone when trying to copy them from laptop to external hard drive

Hi everyone. I apologize if this is a duplicate request by others but greatly need some assistance.

Today, I transferred files from my husband's Samsung Galaxy S7 to the laptop hard drive. Once transferred, I hit "Ctrl-C" to "copy" them from the laptop folder to our external hard drive. I remembered hitting selecting all the photos (over 1000 of them btw), hit Ctrl-C, and when I reached the external hard drive folder to hit "Ctrl-V" to "paste" them into the applicable folder, I would receive an error message for each photo "Item Not Found. Could not find this item. This is no longer located in C:\ (insert C drive folder photos were saved originally).

Worst case I would have expected to photos not to paste into the external hard drive folder, but remain in the original C drive folder since I did a "copy" function not a "cut" function.

Then, to make things more interesting, I went to shut down my PC and it tells me there is an app that is preventing my computer from shutting down, and low and behold it is the app tied to the original C drive folder the pictures were saved, yet when I go into the app, there are no photos in there where it shouldn't be closing.

I think the photos are hung up somewhere and I have no idea how to get them. These pictures are photos my husband had stored on his phone for over 2 years Any help is greatly appreciated.

Welcome to the forum. First option is goto google photos are they there as norammly they are backed up by google