It is common for major Windows 11 updates released by Microsoft to cause issues reported by users and companies shortly after installation. The most recent incidents specifically affect notebooks from the Lenovo and HP brands, in addition to a secondary problem that can impact audio transmission through USB connections, regardless of the equipment manufacturer.
Regarding Lenovo notebooks, complaints are linked to package KB5121003, corresponding to the August 2026 Patch Tuesday, as reported by Neowin. Users of these laptops report that after applying the update, the electrical power is automatically cut off, causing the computers to run only on battery, even when connected to the outlet.
As of now, neither Microsoft nor Lenovo has officially confirmed this issue. However, it is known that package KB5121003 modifies crucial files related to power and battery management, such as battc.sys, cmbatt.sys, and acpi.sys, which could be the source of the failure. Users who opted to roll back the update indicated that the symptom ceased after this procedure.
With HP notebooks, the situation appears more serious, as package KB5121003 is reportedly corrupting the BIOS of the affected machines. A user who contacted HP received instructions to restore the BIOS to its original settings to resolve the failure. This technical support was the one that associated the problem with package KB5121003, although there are reports from other HP laptop users facing similar issues observed in Lenovo models.
Additionally, package KB5124008, referring to the September 2026 Patch Tuesday, has also caused trouble for some users. In this case, Microsoft has already acknowledged the problems. The most notable failure relates to the USB Audio Class 1.0 standard, which is used for communication of audio devices (such as speakers, headphones, and microphones) with the computer via USB cable. Although it is an older specification with successors, it is still widely used.
This defect prevents the audio device from starting correctly or displays an error message when activated. In some situations, the speaker may operate, but only if the standard stereo configuration is maintained. Microsoft has also admitted that update KB5124008 may compromise folder sharing between Windows 11 and Linux virtual machines, in addition to causing the Remote Desktop Services (RDS) component to stop responding.
Generally, problems recognized by Microsoft are corrected in future updates. Meanwhile, a temporary solution is to revert the Patch Tuesday update. To do this, the user must go to Start Menu / Settings / Windows Update / Update History / Uninstall Updates and remove package KB5121003 or KB5124008, depending on the case. The package can be reinstalled after a few days, when the related problems may have been resolved.
Users of Lenovo or HP notebooks can perform this rollback while awaiting statements or fixes from these companies. If the problem persists, it is recommended to contact technical support.