How to delete protected folders/files from previous install

Forgive me if this has been answered but I can't find anything that applies to my situation. I would like to delete the Program Files, Program Files (x86) and ProgramData folders from a previous installation of Win 7 x64. Why I want to do this is because my PC was fried by a power surge despite having a UPS and the only thing recoverable was the contents of the hard drives. So on a new PC running an install of Win 7 from the same disk I copied the contents of the old C: drive to a secondary hard drive so I could recover the files I needed. Now that I have recovered them I would like to delete these folders to get back the storage space. Therefore, in regards to the potential damage to the OS, it doesn't matter who owns or who has permission to modify anything in these folders since they serve no function. I've tried a dozen methods from changing permissions on the folders and everything in them to various user groups and I gather from searching for a solution that Administrator and/or Administrators need to have ownership and full access to these folders and their contents. I am logged in as the "true Administrator" with (technically) full permission to all but the system folders. None of the suggested changes worked. Can I do this at all? I really need the space back that is being hogged by these folders without having to resort to adding another hard drive to get more storage. Reformatting the drive is not an option since I have no way of copying the contents I want to another drive (which I don't have and can't afford, it's a 1TB SSD).