If you can't access files and folders that don't start with My, it is likely
an Ownership and Permissions issue. There are several ways to address this.
Take Ownership/Permissions
Even running as Administrator may leave you without permissions to modify
some files or folders, even ones that you have downloaded and installed. To
access or modify (copy, delete, rename) files or folders you can take
Ownership of (in your Username) and grant yourself Full Control permissions
of the files or folders in question described in the following tutorial.
To avoid having to do this individually for hundreds of files, Take
Ownership of large branches like Program Files folder or Users folder, and
grant yourself Full Control of the folder, all subfolders and files contained
in the folder. In the case of Program Files, you would have full access to
all your programs. In the case of Users folder, you would have full access
to your Music, Pictures, Videos, Documents, etc.
Windows Explorer Run As Administrator
Another way to gain access to modify files and folders includes going to the
Start button, typing in Windows Explorer, right-clicking on this and
selecting Run As Administrator. You should then have "elevated privileges"
to do whatever you wish to files in Windows Explorer.
Unlocker Program
There is also a program called Unlocker that you can use to gain access to
modify files and folders.
http://www.vistax64.com/tutorials/67717-take-ownership-file.html
http://ccollomb.free.fr/unlocker/