Hi All,
After trying all the possible solutions you kindly shared on this thread, unfortunately none of them worked for me.
So I am sharing the solution I found, which worked fine for me on two different ASUS systems (one ROG notebook and one Ultrabook).
<Update>: This applies to 64-bit Intel-based systems. When downloading standalone install packages, please select the appropriate ones for your specific PC. KB numbers might therefore differ.<End of Update>
I made a system restore to a point pre-Windows 8.1 Update failure (in my case it was dates April 8th).
At this point I installed manually and one by one (NOT via Windows Update) each of the .msu files which are part of Windows 8.1 Update, and which you can download from the Microsoft web site from here:
http://www.microsoft.com/en-US/download/details.aspx?id=42335
IMPORTANT: Before doing that you must ensure that KB2919442 is installed on your system, since this is a pre-requisite to install Windows 8.1 Update.
If it is not installed, first of all install that update from here: http://www.microsoft.com/en-US/download/details.aspx?id=42162
IMPORTANT # 2: You must ensure to follow EXACTLY this installation order:
KB2919355, KB2932046, KB2937592, KB2938439 and finally KB2934018.
IMPORTANT # 3: After installing each one of those, you need to restart your PC. Please note that the biggest one - KB2919355 - can take a lot of time for full system restart, just allow Windows to complete all necessary post-installation operations.
As a final consideration, due to my personal experience with unsuccessful attempts to install Windows 8.1 Update on two different systems, I came to this conclusions: The reason of all the time-consuming issues we are all experiencing or have experienced
since April 8th is Microsoft's fault. There was nothing wrong or damaged on our systems (in general, of course some systems might have already been corrupted before installing the update). It was the failed attempts to install Windows 8.1 Update via Windows
Update which somehow damaged our systems, and in most cases none of the clever workarounds/solutions I've seen here worked.
Magically after restoring system to a pre-Windows 8.1 Update state, and by installing that update via the .msu install packages downloaded from the Microsof site and NOT via Windows Update, everything worked perfectly and our systems are no longer damaged
or corrupted, and both shine with a brand new Windows 8.1 Update (which is a nice update, by the way for those who never liked the Metro/Modern UI).
And, especially, there's no need to reinstall the whole Win 8 or Win 8.1 from scratch, loosing all our programs, apps and personalization and therefore needing full working days to bring back machine configuration to actual status.
I can tell you for sure that my solution has already worked fine for few friends/colleagues of mine here in Italy.
I do hope it can help at least some of you to solve this extremely annoying and time-consuming issue.
I've been struggling with it since April 8th and I've wasted all my Saturday on that, but thank goodness I succeeded.
Please let me know if the above is working for you, too, I'd be curious to know.
Good luck!