KB5066791 Windows update failed to install

Question

Trying to update my Windows. I had a few updates pending so I decided to update the system, everything installed perfectly except KB5066791 Security update. I have tried different ways to install the update but nothing works. I have tried safe mode install. manual install nothing works. Those 2 error codes are the most common 0x80071a2d 0x800f0923. Please help!

Answer 1

Please try the following methods below.

• Run the Windows Update Troubleshooter

Press Start then click Settings (Gear icon)

Select Update and Security > Troubleshoot

Select Additional troubleshooters

Under Get Up and Running, select Windows Update

Run the troubleshooter

• Make sure Windows Update and Background Intelligent Transfer services are available and running.

Click Start, type services.msc in the Start Search text area, and then click services.msc in the programs list. If you are prompted for an administrator password or for a confirmation, type the password, or click Continue.

Double-click Background Intelligent Transfer Service.

If the Startup status lists Stopped, click Start and then click OK. If the status is Running, right click then select Restart

Double-click Windows Update.

If the Startup status lists Stopped, click Start and then click OK. If the status is Running, right click then select Restart

• Please try to run SFC and DISM to check for any system errors and corrupted files.

https://support.microsoft.com/windows/using-system-file-checker-in-windows-365e0031-36b1-6031-f804-8fd86e0ef4ca

I look forward to receiving your update and I'm willing to collaborate with you till we resolve the issue. Do keep me informed by clicking "Add comment" below.

Answer 2

tried all of that and it still doesnt work

Answer 3

If the issue still persists, please try performing an In-place Upgrade. It will definitely help in resolving update errors. Performing this can repair broken operating system files while your personal files, settings and installed applications will not be removed.

Few things to check on the PC

• Unplug all external peripherals except for the Mouse, Keyboard, and LAN cable before starting
• Disable or uninstall any third-party Antivirus program to prevent it from interfering with the upgrade

Download the media creation tool (Click Download tool now) and save it to your computer.

https://www.microsoft.com/en-us/software-download/windows10

Open the tool and select Upgrade this PC now.

Make sure to select Keep personal files and apps.

It might take some time to install Windows 10. Your computer will restart a few times; make sure you don’t turn off your PC.

Answer 4

If most methods fail and the In-place upgrade doesn't work, you may need to consider performing the Reset this PC with Keep my files option.

https://support.microsoft.com/en-us/windows/reset-your-pc-0ef73740-b927-549b-b7c9-e6f2b48d275e

Answer 5

Please check and try Jose's accepted solution in the older thread below with a similar problem if it helps.

https://learn.microsoft.com/en-us/answers/questions/5588117/kb5066791-fails-with-0x80071a2d-on-windows-10-22h2