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🧩 SetupDiag (Windows Setup Failure Diagnostic Tool)
Category: Microsoft Official Tools
Author: jmarket (PCHF Founder)
Verified by: PCHF Staff • October 2025
Overview
SetupDiag is Microsoft’s official diagnostic utility for analyzing Windows Setup logs to determine why an upgrade, feature update, or installation failed.
It scans installation and upgrade logs, detects known failure patterns, and generates a report named SetupDiagResults.log with detailed explanations of each error encountered.
The tool supports all Windows 10 and Windows 11 builds, including version 25H2.
SetupDiag can be run locally or offline, making it an essential troubleshooting resource for technicians and advanced users.
It identifies issues such as driver conflicts, insufficient disk space, or incompatible software that prevent successful upgrades.
Key Features
- Automatic Log Analysis: Scans Windows Setup logs and matches errors to Microsoft’s internal database of known issues.
- Offline and Online Usage: Works even if the target system cannot boot successfully.
- Human-Readable Output: Generates an easy-to-read SetupDiagResults.log file summarizing failure causes and suggestions.
- Extensive Compatibility: Supports all modern Windows versions including Windows 10, Windows 11, and Server 2025.
- Portable Utility: No installation required — run directly as a standalone executable.
System Requirements
- Operating System: Windows 10 or Windows 11
- Administrator privileges
- Access to Setup logs located in
C:\$WINDOWS.~BT\Sources\Panther
Usage
- Download SetupDiag.exe from Microsoft’s official documentation page:
- https://learn.microsoft.com/en-us/windows/deployment/upgrade/setupdiag
- Copy the tool to the system where the upgrade or installation failed.
- Run SetupDiag.exe as Administrator.
- Wait for the analysis to complete. The results will be stored in SetupDiagResults.log in the same directory.
Example Command
SetupDiag.exe /Output:C:\Temp\SetupDiagResults.log
Interpreting Results
The SetupDiagResults.log file provides a summary of detected issues. Common examples include:
| Error Code | Meaning | Typical Cause |
|---|---|---|
| 0xC1900101 | Driver failure | Incompatible or outdated hardware drivers |
| 0x8007042B | Unexpected process termination | Background interference or insufficient resources |
| 0xC1900208 | Compatibility hold | Blocked applications or antivirus software |
| 0x8007001F | I/O device error | Disk or storage-related issue |
Verifying Integrity
Microsoft provides SHA-256 checksums for SetupDiag when available.
To verify integrity, use the following command in PowerShell or Command Prompt:
CertUtil -hashfile SetupDiag.exe SHA256
Compare the hash output with the one listed on Microsoft’s official SetupDiag documentation page.
Notes
- SetupDiag can run on any Windows 10 or 11 system, regardless of update state.
- It supports offline analysis using copied log files from other machines.
- Ideal for diagnosing upgrade failures such as
0xC1900101or0x8007042B. - Does not modify system files and can be executed safely multiple times.
Policy
Only official downloads from Microsoft’s website are permitted.
Redistribution or hosting of the SetupDiag executable outside of Microsoft channels is prohibited.
PCHF provides verified documentation and guidance only.
Download
Official Microsoft SetupDiag Download Page
Technical Information
- Publisher: Microsoft Corporation
- Version: 1.6.0.0 (Supports Windows 11 25H2)
- Release Date: October 2025
- License: Freeware (Microsoft Official Utility)
Related Articles
- Windows 11 Media Creation Tool (Official Microsoft Utility)
- DISM (Deployment Image Servicing and Management Tool)
- Windows 11 ISO (Official Microsoft Download)
All content © 2025 PC Help Forum. SetupDiag is developed and maintained by Microsoft Corporation.
All links provided point directly to official Microsoft documentation. Redistribution or modification of the original binary is not permitted.