KB5070886 Won't install on Server 2012 R2 with extended support. Error 0x800F0831

Hello John Potter - (PRL),

The error code 0x800F0831 usually points to a missing prerequisite or servicing stack issue, which explains why the update nearly completes before rolling back. On Server 2012 R2 with Extended Security Updates, this often happens if the required Servicing Stack Update (SSU) or another dependency isn’t in place.

Before attempting the installation again, please ensure the latest SSU for Server 2012 R2 is installed, as KB5070886 will fail without it. It’s also important to confirm that your Extended Security Updates (ESU) licensing and activation are still valid, since expired or misapplied ESU keys can block updates. If the issue persists, reviewing the CBS.log and WindowsUpdate.log after the rollback will usually highlight the missing package or dependency.

Since SQL is running on both servers, it shouldn’t directly block the update, but certain drivers or monitoring tools can interfere. If needed, you can try installing the update in Safe Mode with Networking or after temporarily disabling third‑party services to rule that out.

In summary, once the SSU is current, ESU licensing is validated, and any missing prerequisites are addressed, KB5070886 should install successfully.

I hope this helps, If this guidance proves helpful, please kindly click “Accept Answer” so we know we’re heading in the right direction 😊. And of course, I’m here if you need further clarification or support.

Harry Phan.