Windows 10 update KB4345421

Windows 10 update KB4345421 (Build 17134.166) releases

Windows 10 is once again getting updated in July — Here are more details about the improvements and fixes.

Outside of its regular Patch Tuesday schedule, Microsoft is now rolling out update KB4345421 for Windows 10 version 1803 (April 2018 Update), update KB4345420 for version 1709 (Fall Creators Update), and update KB4345419 for version 1703 (Creators Update) to address several issues.

KB4345421 bumps the version number to build 17134.166, and according to the company it fixes four related networking issues, while update KB4345419 bumps the version number to build 15063.1208, and it fixes three networking related problems.

Windows 10 build 17134.166

Microsoft has announced KB4345421 in the Windows support site, and it’s referred as “July 16, 2018—KB4345421 (OS Build 17134.166)”. If you’re already running the Windows 10 version 1803 on your PC, this update will address these problems:

  • Addresses an issue that may cause some devices running network monitoring workloads to receive the 0xD1 Stop error because of a race condition after installing the July update.
  • Fixes a problem with the DHCP Failover server that may cause enterprise clients to receive an invalid configuration when requesting a new IP address. This results in a loss of connectivity.
  • Addresses an issue that occurs when an administrator tries to stop the World Wide Web Publishing Service (W3SVC). The W3SVC remains in a “stopping” state, but cannot fully stop or it cannot be restarted.
  • Fixes a problem that may cause the restart of the SQL Server service to fail occasionally with the error, “TCP port is already in use”.

Windows 10 build 16299.550

The Fall Creators Update is getting update KB4345420, and the Windows support site referred it as “July 16, 2018—KB4345420 (OS Build 16299.550)”. If you’re already running the Windows 10 version 1709 on your PC, this update will address these problems:

  • Fixes a problem that occurs when an administrator tries to stop the World Wide Web Publishing Service (W3SVC). The W3SVC remains in a “stopping” state, but cannot fully stop or it cannot be restarted.
  • Addresses an issue that may cause some devices running network monitoring workloads to receive the 0xD1 Stop error because of a race condition after installing the July update.
  • Fixes a problem that may cause the restart of the SQL Server service to fail occasionally with the error, “TCP port is already in use”.
  • Addresses an issue with the DHCP Failover server that may cause enterprise clients to receive an invalid configuration when requesting a new IP address. This results in a loss of connectivity.

Windows 10 build 15063.1208

The Creators Update is getting update KB4345419, and the Windows support site referred it as “July 16, 2018—KB4345419 (OS Build 15063.1208)”. If you’re already running the Windows 10 version 1703 on your PC, this update will address these problems:

  • Addresses an issue that may cause some devices running network monitoring workloads to receive the 0xD1 Stop error because of a race condition after installing the July update.
  • Fixes a problem that may cause the restart of the SQL Server service to fail occasionally with the error, “TCP port is already in use”.
  • Addresses an issue that occurs when an administrator tries to stop the World Wide Web Publishing Service (W3SVC). The W3SVC remains in a “stopping” state, but cannot fully stop or it cannot be restarted.

How to download July 16 update for Windows 10

The updates for PCs are available immediately, it’ll download and install automatically, but you can always force the update from Settings > Update & Security > Windows Update and clicking the Check for updates button. You can find more details about the most recent updates in the Windows 10 update history tracker guide.

About the author

Mauro Huculak is a Windows How-To Expert who started Pureinfotech in 2010 as an independent online publication. He has also been a Windows Central contributor for nearly a decade. Mauro has over 14 years of experience writing comprehensive guides and creating professional videos about Windows and software, including Android and Linux. Before becoming a technology writer, he was an IT administrator for seven years. In total, Mauro has over 20 years of combined experience in technology. Throughout his career, he achieved different professional certifications from Microsoft (MSCA), Cisco (CCNP), VMware (VCP), and CompTIA (A+ and Network+), and he has been recognized as a Microsoft MVP for many years. You can follow him on X (Twitter), YouTube, LinkedIn and About.me.