Trying to Copy Steam folder from program files to its own folder

For some reason when I installed steam it installed in my program files folder and subsequently downloaded and launched all my games out that. I want to mod Skyrim and I need to have the game launch NOT from a program files folder so I decided to copy my whole steam library (for simplicity and just to not have all my games downloaded and launched out of there) and pasted it into my C drive like an other folder, circumventing the program files. The problem is it won't let me just delete the steam folder that's located in the program files because it says some files are open or in use. How can I delete the folder in my program files so I don't have duplicates and make sure my games don't launch from there?