Can't rename a file in Windows 7

Have you tried to take ownership of the folders? Right-click > Properties > Security > Advanced > Owner and Take ownership as yourself (not administrator).

Reason is UAC (User account control). You can read more about UAC in this article for example.

When UAC is enabled, all user accounts—including administrative accounts—run with standard user rights.

So to perform tasks that require administrative rights you must elevate the rights of the application.

The reason you can't delete a file created before installing Windows 7 is because you are not the owner. To delete it, run Windows Explorer (or any other file manager) as administrator.

To run Windows Explorer as an administrator, type explore in search field of Start Menu then right-click on Windows Explorer in search results and select "Run as administrator".