Problem with dlls

Hi, I installed the dlls in Windows System32 directory (in Windows 10 64 bits). The dlls are there, for example SDL.dll and avcodec-58.dll. If I run a delphi app with FileExists they are there, but they don't show in the explorer, of course I have the explorer setted to show all files, hidden and system files. If I try to delete them with DeleteFile I don't get any error or message, but they are not deleted. I don't know if it's a global windows problem and if only it's in my install, but the directory show a lot of dlls. Only to restart it's what's coming to my mind and it didn't fix the issue.
I went there because I want to delete the dlls, I have an install of Lazarus where CvLoad works well, so I don't see a reason for it not working in Delphi, but I guess despite I copy all the dlls in the working directory of the app, it keep insisting load some dll from Windows System32 directory.
Some hint of anything to do about it before I just reinstall windows? Thanks very much.