not normal to need to change permissions to copy a file.
I assume you aren't using cut/paste as you wouldn't have the ability to move the original.
those files are owned by the system, its how it works. You aren't the only user on PC, you might be only human one but Windows has a few it uses to do the tasks you ask of it. TrustedInstaller is one, it installs all the apps. System is another. There are more.
its why you need to copy the files, you own the copies, no need to change permissions on them.
just look in Tsk manager/details, there is a column that shows the different users currently on your system, all are needed.