Windows Error 0xC0000221 Image Checksum Mismatch
Windows Error 0xC0000221 Fix is one of the most searched Windows problems in enterprise and home environments. Windows Error 0xC0000221 Fix: End users search for Windows Error 0xC0000221 Image Checksum Mismatch after repeated failures that block email, documents, meetings, or sync workflows. WinAssistPro maps 0xC0000221 to verified repair steps used in production support.
What is 0xC0000221?
0xC0000221 is a Windows-specific failure code associated with Image Checksum Mismatch. When this error appears, Windows cannot complete the requested operation until the underlying configuration, permission, or connectivity issue is resolved.
Boot into Safe Mode with Networking to test whether third-party antivirus or filter drivers trigger 0xC0000221.
Run DISM /Online /Cleanup-Image /RestoreHealth, reboot, then execute sfc /scannow from an elevated Command Prompt.
Windows error 0xC0000221 often reappears after incomplete updates. Capture the exact build number, channel, and user context before changing profiles or reinstalling components.
When image checksum mismatch persists, compare a healthy device on the same network segment. If 0xC0000221 is isolated to one account, rebuild local cache before tenant-wide changes.
What are the symptoms of 0xC0000221?
- Windows stops responding or closes unexpectedly when image checksum mismatch occurs.
- Event Viewer or application logs show 0xC0000221 within the same minute as the user-visible failure.
- Repeated prompts, failed operations, or missing features appear until Windows is restarted or the profile is reset.
- Other users on the same device remain unaffected, pointing to a profile-specific 0xC0000221 trigger.
What causes 0xC0000221 in Windows?
- Damaged registry entries or missing DLL dependencies block Windows from loading required components.
- Disk errors or low free space interrupt Windows while it writes temporary recovery data.
- Network latency, proxy misconfiguration, or TLS inspection breaks Windows communication when 0xC0000221 is logged.
How to fix 0xC0000221 step by step
- Verify the error code
Confirm 0xC0000221 in Windows logs, Event Viewer, or the dialog. Screenshot the full message for change-control records.
- Restart and patch
Close Windows, reboot Windows, install pending OS and Office updates, then retest the exact workflow that triggered 0xC0000221.
- Repair Microsoft 365
Settings > Apps > Installed apps > Microsoft 365 > Modify > Online Repair. This restores Windows binaries linked to 0xC0000221.
- Apply category fix
Open Services (services.msc) and confirm Windows Update, BITS, and Cryptographic Services are running and set to Automatic.
- Validate with test account
Sign in with a clean profile or temporary user. If 0xC0000221 disappears, migrate data instead of reinstalling the whole device.
Quick reference table
| Field | Value |
|---|---|
| Error code | 0xC0000221 |
| Product | Windows |
| Severity | Medium to High |
| Typical fix time | 10–30 minutes |
| Requires admin rights | Sometimes |
Frequently asked questions about 0xC0000221
What does Windows error 0xC0000221 mean?
Error 0xC0000221 signals image checksum mismatch. It indicates Windows could not finish the operation because of configuration, permission, or connectivity limits.
Can I ignore 0xC0000221?
No. Unresolved 0xC0000221 events in Windows can lead to data loss, sync backlog, or recurring crashes for the same users.
How long does a 0xC0000221 fix take?
Most Windows cases clear in 10–30 minutes after restart, update, and Online Repair. Profile rebuilds may add another 15–45 minutes.
Does Microsoft support document 0xC0000221?
Microsoft documents many HRESULT and stop codes. WinAssistPro consolidates 0xC0000221 fixes into a single ordered checklist for faster desk-side recovery.
User reviews
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