Microsoft Windows Error Code 0xC0000051: How to Fix It
Easy 30 minutes Medium Severity
Verified June 2026
- Error Code
- 0xC0000051
- Brand
- Microsoft Windows
- Product Type
- operating_system
- Severity
- Medium
- DIY Difficulty
- Easy
- Estimated Fix Time
- 30 minutes
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Tools You'll Need
- Administrator access
- Disk Cleanup utility
- Command Prompt
How to Fix Error Code 0xC0000051
-
Free Up Disk Space
Back up important files before deleting anything. -
Check Disk Quota Settings
Changing quotas may affect other users on the system. -
Run CHKDSK to Repair File System
Do not interrupt CHKDSK once it starts; it may cause data loss. -
Extend the Partition (If Applicable)
Extending a partition requires contiguous unallocated space next to it. -
Check for Malware
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When to Call a Professional
If you cannot free up space (e.g., due to unknown large files), or if the error persists after running CHKDSK and extending partitions, a professional may need to recover data or repair the disk. Also, if you suspect a hardware failure (e.g., disk clicking), stop immediately and seek data recovery help.Frequently Asked Questions
What does error 0xC0000051 mean?
It means Windows has run out of allocated space in the file system. Usually, this occurs when a disk is full or a storage quota has been exceeded.
Can this error cause data loss?
The error itself does not cause data loss, but attempts to save data when the disk is full can fail. It's important to free up space to prevent further issues.
Will I lose files if I run CHKDSK?
CHKDSK with the /f parameter repairs file system errors without deleting files in most cases. However, it may remove corrupted file entries. Always backup important data first.
Does this error affect all drives?
It affects only the drive or partition where the space is exhausted. Other drives should work normally.
How do I prevent error 0xC0000051?
Keep at least 10-15% of your disk space free, regularly run Disk Cleanup, and monitor disk usage with tools like Storage Sense in Windows.