If you get error code 8000405 installing this fix, and use BIBM to boot Windows 7, then the solution is easy. Boot directly to the windows 7 partition and install the fix. This worked for me. See additional information:https://support.microsoft.com/en-us/kb/3033929
Known issues with this security update
Some users cannot install this security update if their computers meet the following conditions:•Have a multiple-boot configuration of Windows and various distributions of Linux
•Use a non-Windows boot loader
•Have Windows and Linux installed on separate drives
We have been able to verify that systems that have the Windows boot loader enabled as the primary loader are successfully able to install this update and that systems that have a non-Windows boot loader specified as the primary boot loader cannot install the update, even if the user uses that loader to select Windows.
Issue 1 workaround
To work around that issue, you can either use Windows as the default boot loader or you can change your BIOS settings to enable the Windows boot loader directly when you install this update.