How do I delete a User Profile from the C:\Users folder?

I just bought a new PC and the stores profile is still on there (I bought the floor model). I made a new profile for myself and I can not delete the stores profile. I went to Control Panel and deleted it but when I go to c:\users its still there. When I try to delete the profile (c:\users\nex ) It says this folder is shared with other people, are you sure you want to delete. When I select YES, it says "The action can not be completed because the folder or a file in it is open in another program." The File is empty. Please help.