I lost my hard drive and when it was reset up I had some issues with the name the vendor used for the user name. So I added added a name and deleted the old one, which may of been a mistake. When I look under the user name (name next the house icon), I see a different folder structure that I have on my Mac Pro. For example I missing Library folder etc. I have an application folder that won't even open up. How do I repair that?