Windows update error code 2 for Microsoft.NET Framework 4.5,4.5.1...

SFC is now happy
(finally!)

Code:

 Line 28040: 2015-06-22 17:43:28, Info                  CSI    0000034b [SR] Repairing 1 components
 Line 28041: 2015-06-22 17:43:28, Info                  CSI    0000034c [SR] Beginning Verify and Repair transaction
 Line 28042: 2015-06-22 17:43:28, Info                  CSI    0000034d [SR] Repairing corrupted file [ml:48{24},l:46{23}]"\??\C:\Windows\SysWOW64"\[l:20{10}]"ksuser.dll" from store
 Line 28051: 2015-06-22 17:43:28, Info                  CSI    0000034f [SR] Repair complete

Do a new Check for Updates, and attempt to install only the oldest update found.
If it goes in OK, try the rest.
If it fails, post the new C:\Windows\windowsupdate.log file.

In that case, all I can suggest is attempting a Repair of the .NET 4.5 installation using the option in the Programs listing, and see if that helps. If not, you may need to uninstall it, run the .NET Cleanup tool, and then reinstall it.