A clean boot is performed to start Windows by using a minimal set of drivers and startup programs. This helps eliminate software conflicts that occur when you install a program or an update or when you run a program in Windows 10, Windows 8.1, Windows 8, Windows 7, or Windows Vista. You may also troubleshoot or determine what conflict is causing the problem by performing a clean boot.
- You must log on to the computer as an administrator to be able to perform a clean boot.
- Your computer may temporarily lose some functionality when you perform a clean boot. When you start the computer normally, the functionality returns. However, you may receive the original error message, or experience the original behavior if the problem still exists.
- If the computer is connected to a network, network policy settings may prevent you from following these steps. We strongly recommend that you do not use the System Configuration utility to change the advanced boot options on the computer unless a Microsoft support engineer directs you to do this. Doing this may make the computer unusable.
Use the following steps to perform a clean boot:Video: How to do a clean boot in Windows
After the computer is restarted, you will have a clean boot environment. Then, do one of the following, as appropriate for your situation:
- If you could not install or uninstall a program or an update before you performed the clean boot, try to install or uninstall the program or update again.
Note If you receive the "The Windows Installer service could not be accessed" error during the installation or uninstallation, follow How to start the Windows Installer service when system services are not loaded, and then install or uninstall the program or update again.
- If the installation or uninstallation is successful, you have resolved your issue. Follow How to reset the computer to start as usual to reset your computer to the normal startup.
- If the installation or uninstallation still fails, that means this issue is not caused by application or service interference. You may have to go to Microsoft Support for more specific support.
- If you could not run a program before you performed the clean boot, try to run the program again.
- If the program runs correctly, this issue is caused by application or service interferences. Follow How to determine what is causing the issue by performing a clean boot to determine which application or service causes the issue.
- If the program still does not run as expected, this issue is not caused by application or service interference. You may have to go to Microsoft Support for more specific support.
How to determine what is causing the problem by performing a clean boot
How to start the Windows Installer service when system services are not loadedIf you run a Setup program without starting the Windows Installer service, you may receive the following error message:
The Windows Installer service could not be accessed. Contact your support personnel to verify that the windows Installer service is properly registered.The Windows Installer service does not start if you clear the Load system services check box in the System Configuration utility. To use the Windows Installer service when system services are not loaded, you must start the service manually. To do this, follow these steps.
Article ID: 929135 - Last Review: 15 Jan 2017 - Revision: 10