Try this, make a second admin account, log into it, remove all groups from that your main account is a part of (Users/Administrator/etc...) then add Administrator back to your main account's groups. Don't add the "Users" group. Login back into your main and hope fully it resolves the issue like it did for me! You can then delete the extra administrator account.
I think Users takes precedence over more controlling groups for security reasons when you first get a windows account from the installation vs. the control panel way to create accounts.