What is a repair installation?
A repair installation, also called an in-place repair or repair upgrade, runs Windows Setup on top of the existing installation using the same version of Windows or a newer one. Setup rebuilds the operating system from fresh files, then carries over user accounts, personal files, installed desktop applications and most settings. It is the strongest fix that still leaves the user's environment in place, so it sits between file-level repair tools and the destructive options of resetting or reinstalling.
How to run one
- Back up the user's data. A repair install is designed to keep files, but any Setup run on a damaged system carries some risk.
- Get installation media for the same edition and language as the installed Windows, at the same build or newer. Check the current version with
winver. - From inside Windows, double-click the ISO file to mount it (or open the USB drive) and run
setup.exe. - When asked what to keep, choose Keep personal files and apps. If that option is grayed out or missing, the media does not match the installed edition, language or architecture, or it is older than the installed build.
- Let Setup finish; the PC restarts several times. Afterward, run Windows Update and confirm the original problem is gone.
Recent Windows 11 releases also include Fix problems using Windows Update in Settings > System > Recovery, which downloads and reinstalls the current version of Windows while keeping apps, files and settings.
Why it must start from Windows
The keep-everything option exists only when Setup is launched from the running desktop. Booting the PC from installation media leads to a fresh installation instead. If Windows cannot reach the desktop at all, start with the Windows Recovery Environment (Startup Repair, System Restore, or uninstalling a recent update), and if those fail, move on to Reset this PC or a clean install.
What it fixes and what it does not
- Fixes: corrupted system files and component store damage that
sfc /scannowandDISM /Online /Cleanup-Image /RestoreHealthcould not repair, built-in features such as Start or Settings failing for every user, and stuck or failed updates. - Does not fix: hardware faults, a corrupted profile that affects only one user, problems caused by a third-party app (which is carried over), or malware hiding in user data or apps. A seriously infected PC calls for a reimage, not a repair.
Repair install vs other recovery options
| Option | Personal files | Apps | Settings |
|---|---|---|---|
| sfc and DISM | Kept | Kept | Kept; only damaged system files are replaced |
| System Restore | Kept | Rolled back to the restore point | Rolled back |
| Repair installation | Kept | Kept | Mostly kept |
| Reset this PC, Keep my files | Kept | Removed | Reset to defaults |
| Reset this PC, Remove everything, or clean install | Removed | Removed | Removed |
Repair installation on the CompTIA A+ exam
Repair installations fit Core 2 (220-1202) objective 1.2, which covers installation and upgrade types, and objective 3.1, which covers fixing Windows problems such as instability and boot issues. Know that a repair install reinstalls the same version in place while keeping data and apps, that it is started from within Windows, and where it falls in the escalation order: sfc and DISM, then System Restore, then a repair install, then Reset this PC, then a reimage or clean install. Distinguish it from an in-place upgrade, which uses the same Setup process to move to a newer version or edition.