I've had the same problem in Windows 7, and I am the sole user/administrator of the CPU. My permissions are set to full access, but in my case, this is a random occurrence. One day the shortcut on the desktop will work, I will shut down the CPU and the next time I sign in I have no access. I can, however, access "photos" from the taskbar at the top of the CPU every time.
I have "rebuilt" the shortcut several times and it will work and then all of a sudden, I cannot access the shortcut again. I think this is an odd "security" feature, especially since it doesn't occur with any other shortcut (i.e., "my music").
I downloaded the "take ownership" registry entry and it appears when I right click it now, so many thanks. I don't always like the format in "photos" that appears, so to have the old stand-by "my pictures" is welcomed.