my pc not Not able to complete update and taking long time and it is not updating

If Windows Update is taking a long time and not completing, and the device certificate warning is related to Secure Boot certificates, use this path:

1. Run the Windows Update troubleshooter.
   • Go to Start > Settings > System > Troubleshoot > Other troubleshooters.
   • Find Windows Update and select Run.
2. Check the update error condition that matches the symptom.
   • 0x800705b4 means the update took too long or was interrupted.
   • 0x80070002 means the update failed to install.
   • 0x80070005 means access denied or insufficient permissions.
3. If updates are stuck or taking too long, reset the Windows Update cache.
   • Press Win + R, type services.msc, and press Enter.
   • Find Windows Update, right-click it, and select Stop.
   • Open C:\Windows\SoftwareDistribution.
   • Delete the files and folders inside it.
   • Go back to Services, right-click Windows Update, and select Start.
4. Check the network connection.
   • Go to Start > Settings > Network & Internet > Wi‑Fi.
   • Confirm the PC is connected.
5. Temporarily disable antivirus or firewall software if it may be blocking the update.
   • This can help when updates are interrupted or time out.
6. If the warning is about expired Secure Boot certificates:
   • The PC can still start and operate normally.
   • Standard Windows updates continue to install.
   • What stops updating is new boot-related security protections unless the new Secure Boot certificates are installed.
   • Secure Boot should not be disabled as a workaround because that reduces device protection.
7. To stay protected for the certificate issue:
   • Most personal Windows devices receive the new Secure Boot certificates automatically through Microsoft-managed updates.
   • Some devices require an OEM firmware update to apply the new certificates correctly.
   • If the device cannot get the certificate update, check with the PC manufacturer for required firmware updates.
8. If the device is still on Windows 10, note that support ended on October 14, 2025.
   • After that date, Windows 10 no longer receives free software updates, technical assistance, or security fixes from Windows Update.

If the device still cannot update after these steps, Microsoft also lists these options for Windows 10 devices that should be able to update:

• Use Windows 10 Update Assistant.
• Reinstall Windows 10 to return the PC to a cleaner state.
• Take the PC to a qualified repair technician.

References:

• Troubleshoot problems updating Windows
• When Secure Boot certificates expire on Windows devices
• Windows 10 notification: “Your device has reached the end of service”
• October 14, 2025—KB5066837 (OS Build 10240.21161)