Report: Windows 11 KB5121003 Isn't Installing on Many HP Systems, Lenovo & Dell PCs Also Affected

In addition to cutting AC power on Lenovo and HP laptops, Windows 11’s KB5121003 security update is giving a serious headache to some HP systems regarding update installation. A post thread on the Microsoft Learn forum, suggests that the KB5121003 August 2026 Patch Tuesday update normally, but some laptops get stuck at the HP logo after restarting before entering Automatic Repair and rolling the update back.

HP owners are facing a frustrating update failure

Several HP OmniBook X Flip owners have reported almost identical problems when trying to install KB5121003. In some cases, users said they even exchanged their laptops, only to face the same issue on their replacement units.

One reported HP OmniBook X Flip 14 configuration features an AMD Ryzen AI 5 430 processor, 16GB RAM, 512GB SSD, and Windows 11 25H2. The update installs normally at first, but the restart can leave the system stuck at the HP logo.

Things can get worse from there. Windows may enter Automatic Repair after a forced shutdown and eventually undo the update. Some users have also reported 0x800f0845 as the installation error.

Microsoft has yet to officially acknowledge this specific HP boot problem. That leaves affected users without a confirmed fix, although some reports point toward possible workarounds. That said, a user has alleged that “HP said KB5121003 corrupted the BIOS settings which was causing the problem.”

Interestingly, it seems the problem may not be limited to HP systems. One IT administrator working for an MSP said that users across different companies have reported similar problems on Lenovo and Dell PCs.

HP support points users toward a BIOS workaround

One HP OmniBook X owner said HP support recommended loading the BIOS default settings. After doing that, the user managed to install the newer KB5120998 preview update, while KB5121003 later disappeared from the pending update queue. Another user reported successfully installing KB5121003 on a replacement HP OmniBook X Flip after installing updates individually. However, they could not confirm whether that process was responsible for the successful installation.

KB5121003 has already caused several other problems

While the HP boot issue remains unresolved, Microsoft has dealt with several other KB5121003-related problems. Some ARM64 PCs were affected by New Outlook and Teams launch issues after installing the update. Microsoft also investigated game crashes and freezes linked to KB5121003. The company later identified RGB software as a factor behind some of those crashes and provided a workaround.

If you are reading this and are affected by the similar issue on your HP systems, let us know in the comments below.

via: Neowin