I'm wondering if this has something to do with your Homegroup. I noticed on one of your previous screenshots that you have an Admin account and a homegroup user account.
You could try disabling sharing and see if it makes any difference. It's also possible that someone on your homegroup has disabled some permissions for you.
See this tutorial regarding the permissions issue for homegroups: http://www.thewindowsclub.com/share-files-windows-8-homegroup-network