File in old hard drive locked, cannot gain access

Hi all!
I've searched across the web for help with this and nothing has seemed to work so far. I pulled a hard drive out of my old Windows 7 (I think) PC and I was trying to salvage some old family photos. I found a file with a lock icon on it. It allows me inside, but all the photos inside have lock icons on them also and I can't open, edit, or move them (though I can delete them). I've tried switching ownership rights to me through my Windows 10 PC but that doesn't remove the lock icons or grant me access. I've looked at the Advanced Security Settings and I've changed my access to Full Control of the file and all subfiles and folders. Still, the files and subfolders/files are locked with the icon.
Does anyone know a solution? I'll provide specs if they're needed, though I assume this is an OS issue more than hardware.

I shall try to follow this thread as I have a very old 10MB HD on a 14 lbweight Laptop that crashed out half a lifetime away - tucked away somewhere I hope. probably using MS dos 3.0 or earlier before windows. Its only a potential project that defeated me at the time for when I am a much nearer death.

It was my mom's PC, and to my knowledge, there wasn't any encryption software added when she used it.
I have the tower the hard drive came from, but it's not compatible with the monitor I have. I don't wanna have to buy another one just to gain access to the files.

@Jake1988, can you copy the files? The easiest way to remove all security permissions is to copy them to a USB. Its Fat32 format doesn't support ntfs security attributes. If the copies still have the lock icon and you cannot open them then they are likely to be encrypted. Could be Bitlocker, some editions of W7 had it. If so, you'll need to boot up the old PC to read them.

BitLocker Drive Encryption in Windows 7: Frequently Asked Questions