Windows terminated because of a critical user-mode subsystem failure. The identifier alone does not establish a user-specific cause or a failed part.
Protect your files first
Back up important files when possible. If the drive is encrypted, locate the BitLocker recovery key before recovery changes. Stop if storage appears to be failing or this is a work or school managed PC.
What this code tells you
Windows terminated because of a critical user-mode subsystem failure.
This is a researched code brief, not a confirmed diagnosis for your PC. Verify the exact code and any device-specific action against the official references below.
The next useful clue is the exact screen, app, device, or log where it appeared. Record the Windows build and what changed just before the error. Do not treat a matching number from another error family as the same problem.
Check the context
The useful investigation focus is system integrity, recent security or update changes.
- Does Windows start normally, only in Safe Mode, or not at all?
- What Windows build and device model are affected?
- What changed before the problem appeared?
- What exact error text, driver name, KB number, or Event Viewer provider accompanies the code?
Safer checks to try
Protect files before disk or recovery actions Low risk
- Back up important files to a separate destination before any operation that might write to the startup disk.
- If the drive is making unusual sounds, frequently disappearing or reporting severe I/O errors, avoid repeated retries and contact a recovery professional.
- Do not format, wipe, recreate partitions or reinstall Windows as an automatic first step.
After this check, see whether the original error appears again. If it does, record the new timestamp and continue with the next evidence-based step.
Check recent changes and reversible rollback options Low risk
- Review updates, devices, and third-party software installed around the first failure.
- Use a supported Roll Back Driver option if a specific driver update clearly preceded the problem.
- Avoid registry cleaners, driver-updater bundles and random unsigned download sites.
After this check, see whether the original error appears again. If it does, record the new timestamp and continue with the next evidence-based step.
When to stop
Back up data and locate any BitLocker recovery key before advanced recovery steps. Stop for unstable storage or signs of electrical damage.
If Windows will not start repeatedly, the drive is unstable, or the device belongs to work or school, ask the appropriate manufacturer or IT team for help. Do not share a BitLocker key, product key, password, or full memory dump in a public search box.
Keep track of your checks
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