Microsoft, Windows 11 It prepared unplanned emergency patches to fix the serious problems caused by the security updates it introduced on September 8. Company, September 14 It targeted outages in Remote Desktop connections, a folder sharing error in Hyper-V-based Linux virtual machines, and some USB audio issues with dated packages. However, Microsoft’s documentation shows that the problems on some devices using USB Audio Class 1.0 have not yet been completely eliminated. Therefore, which version of Windows 11 you use directly determines the update you need to install.
The starting point of the problems is the September security updates released for Windows 11. For example, offered for Windows 11 26H1 KB5124012caused stability issues on the Remote Desktop Services side in some enterprise environments. Microsoft confirmed that RDP connections may drop after a few minutes, logon issues may occur, and servers may become unresponsive during Remote Desktop configuration. However, the Microsoft Management Console, RDS License Diagnostic, File Explorer and Windows Update page may also stop responding on some systems.
The impact of the September update was not limited to Remote Desktop Services, some applications using Hyper-V also experienced problems. In Linux virtual machines managed by HCS, folders shared via Plan9 may not appear in the guest operating system or users cannot access these folders. Microsoft clearly lists this error among the known problems with KB5124012. Claude Cowork who needs Plan9 folder sharing and Windows Subsystem for Linux (WSL) While affected by this issue, standard Hyper-V virtual machines not using Plan9 do not experience the same issue.
On the other hand USB Audio Class 1.0 Some speakers, microphones and other audio devices may not work properly after the September update. Affected devices may not start, may not produce sound, or may not appear in Device Manager. Code 10 It may show error. On some computers, the volume controls remain at zero and the volume options in the Settings application may not respond. Microsoft is fixing a separate problem with 8-channel and 3D audio modes with the immediate update, but continues to work on other USB Audio Class 1.0 issues.
Microsoft fixes major bugs with urgent Windows 11 patches
Since Microsoft has prepared separate packages for different Windows 11 versions, it is important to check the update number. PCs using Windows 11 26H1 KB5129194Systems using Windows 11 23H2 KB5129242 is getting the update. In addition, suitable corporate devices registered to the hotpatch program running Windows 11 24H2 and 25H2. KB5129241 reaching. While KB5129194 resolves the Remote Desktop Services issue, it also protects against the Windows User-Mode Power Service privilege escalation vulnerability coded CVE-2026-62721.
KB5129241 fixes Remote Desktop Services and Hyper-V Plan9 issues, as well as the bug in 8-channel and 3D USB audio modes. However, Microsoft clearly states that the emergency patches do not eliminate all problems on the USB audio side. USB Audio Class 1.0 devices may still experience Code 10 errors, lost audio output, unresponsive volume controls, or issues with the Settings app. If you are using one of these devices, you can check the operation of the speaker, microphone or USB audio interface after the update.
The installation method also varies depending on the Windows 11 version on the computer. You can get the KB5129194 package for Windows 11 26H1 from Windows Update and check the update from Windows Update settings. For KB5129242 on Windows 11 23H2 side Settings > Windows Update > Advanced options > Optional updates You can follow the path. Microsoft’s Turkish support documents also use the name “Optional updates” for this menu and offer the Download and install option in available packages.
Eligible Windows 11 24H2 and 25H2 computers in the Hotpatch program receive the KB5129241 package via Windows Update. If you have previously installed the September security update, you do not need to restart the computer after this hotpatch package. After July 28, 2026, Microsoft also changed the restart method of Windows updates and began to bundle packages that require a restart with the monthly security update. Thus, Windows reduces the number of reboots required per month for these updates.
The immediate patches address confirmed issues with Remote Desktop Services and Plan9 folder sharing. In contrast, Microsoft USB Audio Class 1.0 It continues to work on some bugs affecting its devices. To manually check for updates in Windows Update, go to Start > Settings > Windows Update. Check for updates You can use the option. Microsoft also offers the “Get the latest updates as soon as they become available” option for users who want to receive non-security fixes sooner.