Windows 11 Upgrade gets stuck at 99%

Question

Windows 11 Upgrade gets stuck at 99%

Minh Vu 40

Hi guys

Could someone please help me to fix this issue? Windows 11 Upgrade has been stuck at 99% for almost a day. The storage is around 500 GB available. My device model is HP EliteDesk 800 G5 Desktop Mini

I have tried to uninstall and re-install the upgrade again but it did not work. Are there any tricks to make the Win11 upgrade work?

Appreciate your help!

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2 answers

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Answer 1

Hi Minh,

When a Windows 11 upgrade stalls at 99% for many hours, it usually indicates a driver or compatibility hang rather than a storage issue. On HP EliteDesk 800 G5 systems, the most common culprits are outdated Intel Management Engine Interface, BIOS firmware, or graphics drivers. First, ensure the BIOS is updated to the latest revision from HP’s support site, and install the latest Intel chipset and MEI drivers before retrying the upgrade.

If the upgrade still hangs, disconnect all non‑essential peripherals (USB drives, docking stations, external monitors) and temporarily disable third‑party antivirus. Run sfc /scannow and DISM /Online /Cleanup-Image /RestoreHealth from an elevated Command Prompt to repair any system file corruption. Then, instead of relying on Windows Update, download the Windows 11 ISO from Microsoft’s official site and perform the upgrade using the Media Creation Tool or setup.exe from the ISO. This bypasses some of the update pipeline issues.

If the system continues to freeze at 99%, check C:\$WINDOWS.~BT\Sources\Panther\setuperr.log and setupact.log for the exact blocking driver or service. Often you’ll see entries pointing to outdated drivers that need removal or update before the upgrade can complete.

I hope you've found something useful here. If it helps you get more insight into the issue, it's appreciated to accept the answer. Should you have more questions, feel free to leave a message. Have a nice day!

Harry.

Answer 2

If your Windows 11 upgrade is stuck at 99%, there are several troubleshooting steps you can take to resolve the issue:

Check for Updates: Ensure that your Windows 10 is fully updated before attempting the upgrade again. Sometimes, pending updates can interfere with the upgrade process.
Free Up Storage Space: Although you mentioned having 500 GB available, ensure that you have at least 20 GB of additional free space for the upgrade process. You can use Disk Cleanup to remove temporary files and system junk.
Restart the Upgrade: If the upgrade is still stuck, try restarting your computer. After rebooting, check if the upgrade continues or completes.
Use the Installation Assistant: If the upgrade through Windows Update is not working, consider using the Windows 11 Installation Assistant from Microsoft's website. This tool can help facilitate the upgrade process.
Check Device Manager for Errors: Open Device Manager and look for any devices with a yellow exclamation mark, which indicates driver issues. Update or uninstall problematic drivers and then try the upgrade again.
Review Event Logs: Use Event Viewer to check for any logs that might indicate what is causing the upgrade to hang. Look for hardware or driver-related issues.
BIOS Settings: Ensure that TPM 2.0 and Secure Boot are enabled in your BIOS settings, as these are required for Windows 11.
Repair or Remove Unsigned Drivers: If there are any unsigned drivers, consider repairing or removing them, as they can cause issues during the upgrade.

If these steps do not resolve the issue, you may need to consider performing a clean installation of Windows 11 using a bootable USB or ISO file, ensuring that you back up your data first.

References: