What this code can mean
Windows cannot access the boot device during startup. Causes may involve boot configuration, storage access or a recent system change.
Possible causes to investigate
- Storage or boot configuration change.
- Storage-controller driver issue.
- Failed update or disk problem.
Safer troubleshooting order
- Record the message and recent settings changes.
- Check whether the drive is detected by official diagnostics.
- Use Windows Recovery if needed and keep the BitLocker key available; do not format partitions.
Protect the boot drive before changing storage settings
Windows can no longer access the device or path it expects to boot from. Recent firmware or storage-mode changes, update failures and drive problems can produce similar symptoms. Avoid toggling SATA/AHCI/RAID settings at random or formatting the disk. If the drive is missing in firmware diagnostics, focus on data and hardware before software repair.
Details to keep: Record any recent BIOS/firmware or storage changes, whether the drive appears in diagnostics, the exact screen and backup/BitLocker status.
Use the code with the full message, Windows version, recent changes and diagnostic evidence. Back up important files before recovery or servicing.
Before applying a code-specific fix
Windows error codes can vary by operation and version. Match the complete message, Windows build and update or driver involved, then follow the diagnostic order on this page before attempting a disruptive recovery.
Related guides
Need help narrowing it down?
Error still repeats?
Keep the full code, update/driver name and the step that failed available.