Destination Folder Access Denied

Hi there;

I'm in somewhat of a conundrum, because having managed to successfully install every expansion pack and apply all the other edits, when it comes to extracting the .dll file from the ultimate fix crack to the bin base game, I get the following error message. 

Destination Folder Access Denied: You need permission to perform this action.

I've done everything I could think of and research, I've turned my anti viruses off, I've tried to edit the permissions on the parent files, I've tried to copy the files to my desktop and move them from there, I've tried to copy and paste the file into the folder, nothing is working. I've reinstalled the game twice, same problem, really got no idea what to do next and any help would be appreciated. Thank you.