encypted files unable to share access

Question

I had a laptop with Windows XP many years ago and I used EFS to encrypt some personal images. Later I saved those in an external hard drive while doing a back up of all my files. Now that I have a new laptop with Windows 10 Home edition (and without access to the old one), I am trying to access the files, so far without success.

I have already granted permissions to the new laptop to access all files files of the hard drive by editing the Group or user names and the Advanced Permissions under the security tab of the Properties. I also changed the Auditing,
I did the same for the images themselves (granted permissions),
And I used cipher \d as the administrator with the Command Prompt.

But still the Encrypt contents to secure data box -under the Advanced options of the General tab in the Properties of the images- is checked and greyed out. Looking at the Details, if I want to Add... a User who can access this file: I get this prompt:

Is there another way that I can access the files? or another way to remove the encryption?