Windows 8.1 Update 1 has been touted as a much needed release for the Windows 8.x OS. Some have stated that it's what Windows 8 should have been in the first place. Microsoft is definitely playing catch-up with its subsequent releases, providing better features for those wanting to use the latest operating system without having to give up something in the process.
As successful a release as Update 1 appears for many, there is a minority of users where the update fails to install for one reason or another. Common installation problems result in errors 80070020, 8007312, 0X800f081f, and 0x80071a91.
Some of the problems have been attributed to issues that existed already before the update was released, while others have surfaced as resulting in corrupted downloads from Windows Update. Despite the exact issue, there have been a few solutions communicated that could help get Update 1 installed. It's pretty important that Update 1 be installed, considering that without it Windows 8.1 users will no longer receive security updates. Update 1 is a required installation.
So, here's a few fixes that are available.
For error 0x80071a91, Microsoft has produced a special hotfix. The associated KB Article is 2939087. Microsoft gives no indication about the actual source of the problem, just that a special hotfix is available to help alleviate the issue.
The hotfix can be obtained through Windows Update, or downloaded from the KB Article itself. Depending on the OS (Windows 8.1 x86, Windows 8.1 x64, orR2), there is a separate download for each affected version.
Errors 80070020, 80073712, 0X800f081f
These error numbers seem to indicate that there was an existing problem with Windows, and more specifically in the Windows Update components themselves. To resolve these errors, Windows Update must be fixed, remnants of the original failed Update 1 installation must be removed, the WinSxS folder cleaned up, and Update 1 reinstalled.
You can find an 8-step process for this in Microsoft's Windows forums: Windows 8.1 Update 1 Failing to Install with errors 80070020, 80073712 and 0x800f081f
I've heard from a few people, myself, who have used the steps in the Windows forum with success and were finally able to install Update 1.
UPDATE (May 5, 2014): KB291355 was rereleased to fix 80073712.
Error 0x8E5E03FA will produce an error message stating that…
Windows failed to install the following update with error 0x8E5E03FA. Update for Windows (KB2919355)
Per a blog post by Abhijit Deshpande, the problem was identified in the CBS.log file that showed the error was actually in the JET_errReadVerifyFailure component. The solution is the stop the cryptsvc service, rename the edb.log file and restart the cryptsvc service.
Full details here: Windows failed to install the following update with error 0x8E5E03FA
Error 800F0922/Cisco VPN Client
There are now reports that the Cisco VPN client is causing issues with teh installation of KB2919355. Uninstalling the offending software will allow Update 1 to successfully install.
Details in this thread on the Microsoft forums: Windows update KB2919355 fails to install - Error code 800F0922
Missing Administrative or System Tools Folders
Another potential issue for some folks has been identified where renaming or moving folders installed by the previous OS (most likely an upgrade from Windows 7) can cause the installation to fail. See the following: Moving or Renaming Administrative and System Tools Folders Cause KB2919355 Installations to Fail