My computer is not able to install this latest update from Microsoft. It has already been upgraded to 8.1 without any issues.
I ran ProcessMonitor and found this:
The process details:Date & Time: 2014-04-26 05:30:50 PMEvent Class: File SystemOperation: SetLinkInformationFileResult: ACCESS DENIEDPath: C:\Windows\WinSxS\amd64_microsoft-windows-b..nager-efi.resources_31bf3856ad364e35_6.3.9600.16384_en-gb_680d99c9c1bb411e\bootmgr.efi.muiTID: 3056Duration: 0.0000421ReplaceIfExists: TrueFileName: \SystemRoot\WinSxS\amd64_microsoft-windows-b..nager-efi.resources_31bf3856ad364e35_6.3.9600.17031_en-gb_68408c0dc1958b90\bootmgr.efi.mui
Description: Windows Modules Installer Worker
Company: Microsoft Corporation
Version: 6.3.9600.17031 (winblue_gdr.140221-1952)
Command Line: C:\WINDOWS\winsxs\amd64_microsoft-windows-servicingstack_31bf3856ad364e35_6.3.9600.17031_none_fa50b3979b1bcb4a\TiWorker.exe -Embedding
Parent PID: 672
Session ID: 0
User: NT AUTHORITY\SYSTEM
Auth ID: 00000000:000003e7
Started: 2014-04-26 05:21:13 PM
Having a look at the permissions on the bootmgr.efi.mui files in both referenced locations shows that SYSTEM can only read and execute these files, which is most likely why the update fails.
My machine originally had a local account, and when I installed the 8.1 upgrade it changed my local account to a live account against my wishes. This should not have anything to do with it, as Windows Update does not run as me, right?
Is it safe to change the permissions so that SYSTEM has write access as well?
EDIT: After all this, the solution found here is quite simple: just reboot and only open Windows Update and install the update. It seems some files might have been held by other processes.