Microsoft Ships Emergency Patches to Fix Remote Desktop Failures

Microsoft has released out-of-band updates for Windows to fix failures in Remote Desktop Services (RDS) that appeared after the September security rollup. The patches also address problems with Hyper-V and USB audio on certain versions of the system.

What broke

The September 2026 security updates destabilized RDS on affected machines: users couldn't connect over RDP or sign in, and some servers stopped responding altogether. The problem turned out to be widespread — administrators started complaining about it almost immediately after installing the patches. Adjacent components and tools could hang as well: the Microsoft Management Console (MMC), the RDS Licensing Diagnoser, File Explorer, and even the Windows Update page.

As a stopgap, Microsoft had earlier offered workarounds through Group Policy while a full fix was being prepared. Removing the September updates also helped — but doing so stripped the security fixes off the system along with them, which is hardly an ideal solution.

Which updates were released

On September 14, the company released several out-of-band patches at once:

• Windows 11 26H1 — KB5129194
• Windows 11 24H2 and 25H2 — KB5129195
• Windows 10 21H2 and 22H2 — KB5129236
• Windows Server 2025 — KB5129235
• Windows Server 2022 — KB5129237

The server updates fix the RDS failures introduced by patches KB5122871 (for Windows Server 2025) and KB5122882 (for Windows Server 2022). The Windows 11 26H1 update is available through Windows Update, Windows Update for Business, the Microsoft Update Catalog, and WSUS, while the server versions are available through the Microsoft Update Catalog.

Hyper-V and audio

The out-of-band updates for Windows 11 also fix a Hyper-V bug that affected applications using virtual machines managed by the Host Compute Service. When sharing folders from a Windows host with Linux guests over the Plan9 protocol, the shared directories either failed to appear in the guest system or turned out to be inaccessible.

Some of the audio problems have been resolved too: certain USB Audio Class 1.0 devices failed during multichannel playback (8-channel and 3D modes), although they worked fine in ordinary stereo. Even so, USB audio hasn't been fully licked. According to Microsoft, on some devices of this class the sound may disappear entirely after the September patch: an error appears in Device Manager reading “This device cannot start (Code 10),” the volume controls freeze at zero, and the sound settings stop responding. The company has promised to release a fix for the remaining issues later.

Source: Bleeping Computer