Windows PXE Boot Issues – KB4493467 (April 9, 2019)

Microsoft has acknowledged an issue with PXE boot affecting Windows 8.1 and Windows Server 2012 R2 systems caused by a Security-Only update (KB4493467) released on April 9, 2019.

The Issue:

After installing this update, there may be issues using the Preboot Execution Environment (PXE) to start a device from a Windows Deployment Services (WDS) server configured to use Variable Window Extension. This may cause the connection to the WDS server to terminate prematurely while downloading the image. This issue does not affect clients or devices that are not using Variable Window Extension.

The Workaround:

To mitigate the issue, disable the Variable Window Extension on WDS server using one of the following options:

Option 1:
Open an Administrator Command prompt and type the following:

Wdsutil /Set-TransportServer /EnableTftpVariableWindowExtension:No

Option 2:
Use the Windows Deployment Services UI.

  1. Open Windows Deployment Services from Windows Administrative Tools.
  2. Expand Servers and right-click a WDS server.
  3. Open its properties and clear the Enable Variable Window Extension box on the TFTP tab.

Option 3:
Set the following registry value to 0:

HKLM\System\CurrentControlSet\Services\WDSServer\Providers\WDSTFTP\EnableVariableWindowExtension”.

Restart the WDSServer service after disabling the Variable Window Extension.

Microsoft is working on a resolution and will provide an update in an upcoming release.

Windows 10 Automatically Uninstalls Problematic Software Updates

Patch Management is an important role of a Sysadmin in the Enterprise, because securing endpoints with security updates to keep systems secure and functional, receive fixes that resolve issues, and patch security holes is highly important. However, with the frequency of security updates which are released these days, patch management tasks feels like a full-time job!

For the most part, monthly patches are straight forward, however in recent months, they have been problematic where they have caused system crashes, blue screens, application functionality issues, and introduced other bugs. Some faulty patches are quickly reversed or rectified by Microsoft, while others go unfixed for a longer duration causing further duress and downtime in many organizations. This has been a major pain point for Sysadmins in the field.

Well, we may have some reprieve from these buggy patches. Microsoft has announced that it will start uninstalling problematic patches automatically from Windows 10 systems when it detects a startup issue due to incompatibility or issues stemming from a recently installed patch. The following notification will be presented:
“We removed some recently installed updates to recover your device from a startup failure.”

According to this KB4492307 posted by Microsoft, the problematic patch will not be reinstalled for 30 days to allow Microsoft and it’s partners to investigate and fix the issues. This process seems like a good proactive approach by Microsoft to get a handle of buggy patches, however more information is needed in terms of how this will work with detection, deployments, and compliance of these patches using ConfigMgr and WSUS as mechanisms for patch management in the enterprise. Time will tell, we hope!

KB3035131 March 2015 – LogonUI.exe Error

We have discovered an issue with one of the patches from March 2015, KB3035131 against our Windows 8.1 systems in VMware VDI. Upon installation of this patch, Windows 8.1 systems are unusable as they are presented with a LogonUI.exe error on startup as seen below. In order to get the systems in working condition, the only resolution at this point is to revert to a previous snapshot and disable the 3035131 patch from installing on these Windows 8.1 systems.

memory_error_2015-03-13

There’s not much info on the Internet regarding this particular issue, or at least one that I can find, however there are some mentions of the use of StartIsBack or Classic Shell, but we are not using them. It will be interesting to know if others have encountered a similar experience, what are the known causes, and if there’s a fix to rectify this issue.