QuickBooks Error C=51: Damaged QBW Company File

Protect your data before attempting repairs:

1. Close QuickBooks on all computers
2. Navigate to company file location
3. Create new folder: Desktop\QB_Recovery
4. Copy these files to QB_Recovery folder:
   • CompanyFile.qbw (main company file)
   • CompanyFile.qbw.tlg (transaction log)
   • CompanyFile.qbw.adr (auto data recovery - if exists)
   • CompanyFile.qbw.nd (network data - if exists)
5. Verify all files copied successfully
6. DO NOT delete original files yet

Use File Doctor to diagnose and repair corruption:

1. Download QuickBooks Tool Hub from Intuit website
2. Install Tool Hub (right-click → Run as administrator)
3. Launch Tool Hub
4. Click "Company File Issues" tab
5. Click "Run QuickBooks File Doctor"
6. Browse to damaged company file location
7. Select your company file from the list
8. Select "Check your file" radio button
9. Enter QuickBooks admin username and password
10. Click "Diagnose File" button
11. Wait for scan to complete (may take 15-45 minutes)
12. Review diagnostic results

If File Doctor cannot repair, use automatic backup:

1. Navigate to company file folder
2. Look for file with .ADR extension:
   ADR File Example

   Copy

   CompanyFile.qbw.adr

3. If .ADR file exists:
   • Open QuickBooks
   • File → Open or Restore Company
   • Select "Restore a backup copy"
   • Next → Local backup → Next
   • Browse to folder with .ADR file
   • Change file type filter to "All Files (*.*)"
   • Select the .ADR file
   • Click Open
4. Save restored file with new name (e.g., CompanyFile_Recovered.qbw)
5. QuickBooks will restore data from .ADR file
6. Open restored file and verify data integrity

Use built-in QuickBooks repair tools:

1. Open QuickBooks (do not open company file yet)
2. File → Utilities → Verify Data
3. Wait for verification to complete
4. Review results:
   • If problems found: Run Rebuild Data
   • If no problems found: Try opening file normally
5. To rebuild: File → Utilities → Rebuild Data
6. Click OK on backup prompt (QuickBooks creates backup first)
7. Wait for rebuild to complete (may take 10-60 minutes)
8. When complete, run Verify Data again to confirm repair

Good: "QuickBooks detected no problems with your data"
Bad: "Your data has lost integrity"
Action Required: "Problems found - run Rebuild Data"

If all repair attempts fail, restore from backup:

1. Locate your most recent manual backup file (.QBB)
2. Open QuickBooks
3. File → Open or Restore Company
4. Select "Restore a backup copy" → Next
5. Select "Local backup" → Next
6. Browse to backup file location
7. Select the .QBB backup file
8. Click Open → Next
9. Choose restore location
10. Save with new file name (CompanyFile_Restored.qbw)
11. Click Save
12. QuickBooks will restore the backup
13. Open restored file and verify data

After successful recovery, verify all data:

1. Open recovered/restored company file
2. Run several reports to verify data:
   • Profit & Loss (check for missing transactions)
   • Balance Sheet (verify account balances)
   • Trial Balance (ensure debits = credits)
   • Customer Balance Detail
   • Vendor Balance Detail
3. Compare reports to known good data (printed reports or previous backup)
4. Test key functions:
   • Create test invoice
   • Enter test bill
   • Run payroll (if applicable)
5. If everything works correctly, create new backup immediately
6. Run Verify Data one more time to confirm file health

Prevent future data loss with proper backups:

1. Configure automatic backups:
   • File → Create Backup → Options
   • Set backup location (not same drive as company file)
   • Enable "Remind me to backup when I close" every 4-7 times
   • Keep at least 3 backup copies
2. Create manual backups before major activities:
   • Before year-end closing
   • Before QuickBooks updates
   • Before major data imports
   • At least weekly during normal operations
3. Store backups in multiple locations:
   • External hard drive
   • Cloud storage (after backup is complete)
   • Different physical location (offsite)