See some of the most common upgrade and installation errors for Windows 10 and Windows 11, and what you can do to try to fix them.

Describes how to troubleshoot problems that occur when you install, uninstall, or upgrade a program on a Windows-based computer by using Windows Installer.

Learn how to troubleshoot problems updating Windows. Find answers to common questions and issues installing Windows updates.

When upgrading to, or updating, Windows 10, you might encounter the error “We couldn’t update system reserved partition”, error code 0xc1900104, or error code 0x800f0922.

Learn how to run Windows Update Troubleshooter to resolve errors downloading or installing Windows updates.

Jan 12, 2007 · Describes how to use the System File Checker tool to troubleshoot missing or corrupted system files in Windows.

Oct 14, 2025 · The Program Install and Uninstall troubleshooter helps you automatically repair issues when you're blocked from installing or removing programs. It also fixes corrupted registry keys.

Describes how to fix error code 0xC1900102, 0x80070004, and other errors when you install Windows 8.1 or 10 that are caused when the Users or Program Files folder is redirected.

Windows Update error code "0x643" and Windows Installer error code "1603" are generic error codes. Typically, these error codes mean that the update was not installed.

The Windows Installer Service could not be accessed. This can occur if you are running Windows in safe mode, or the Windows Installer is not correctly installed. Contact your support personnel for …