Troubleshooting 'Another Installation is in Progress' in Windows 11 26H2

If you're seeing the message 'another installation is in progress' during your Windows 11 26H2 upgrade, it means a previous installation or update hasn't finished. This error can block your upgrade, but there are steps you can take to fix it and continue with your installation.

What does the error message mean?

The message 'another installation is in progress' means that Windows is currently handling another installation. This could be because of an unfinished update, a software installation, or a Windows component that hasn’t completed. The 26H2 upgrade cannot start until the ongoing process is resolved.

Before you start

Before trying to fix this issue, make sure that:

• You have administrative rights on your device.
• All applications are closed, especially those that may be updating in the background.
• You have saved all your work, as some steps may require restarting your computer.

Steps to resolve the installation error

To resolve the 'another installation is in progress' error, follow these steps:

1. Press Windows + R to open the Run dialog.
2. Type services.msc and hit Enter.
3. Find 'Windows Installer' in the list.
4. Right-click on 'Windows Installer' and select 'Stop'.
5. Right-click on 'Windows Installer' again and select 'Start'.

This can often clear up any stuck installation processes causing the blockage.

Using Task Manager to check for ongoing installations

To see if another installation is running, use Task Manager:

1. Press Ctrl + Shift + Esc to open Task Manager.
2. Click on the 'Processes' tab.
3. Look for processes named 'msiexec.exe' or other installation-related tasks.

If you spot such processes, it means an installation is ongoing. You can right-click these processes and select 'End Task' to stop them if you're sure they aren't needed.

Checking installation logs

To get more details on the installation error, check the Windows installation logs:

1. Open the Run dialog with Windows + R.
2. Type C:\Windows\Logs\CBS\CBS.log to view the CBS log, which has information about the installation process.

These logs can help identify specific issues that occurred during the upgrade.

Clearing installation cache and restarting

If the issue continues, clearing the installation cache might help:

1. Open the Run dialog with Windows + R.
2. Type %temp% and hit Enter to open the Temp folder.
3. Select all files and folders in this directory and delete them.
4. After clearing the cache, restart your computer.

Once your system is back on, try the upgrade process again to see if the error is resolved.

Best practices to prevent future issues

To avoid seeing the 'another installation is in progress' error during future Windows upgrades, consider these best practices:

• Ensure all prior updates and installations are completed before starting a new upgrade.
• Regularly check and apply any Windows updates.
• Avoid interrupting installations or upgrades once they begin.
• Keep your system clean by periodically deleting temporary files and unused applications.

Conclusion

If you've followed these steps and are still having issues, consider contacting Microsoft Support for further help.