File Corruption & Recovery

Fix Excel Cannot Repair a Severely Corrupted Encrypted File

Maira Mehtab Sep 22, 2026 869 views

Question details

A password-protected Excel cash-flow workbook has become unreadable, and its file size drastically decreased to 4 KB, making Excel unable to repair it.

Product: Microsoft Excel
Device & OS: not provided
Scenario: Attempting to open or repair a password-protected workbook that has experienced severe data loss and file size reduction.
Observed behavior: Excel displays an error stating it cannot repair the encrypted file, and the file size is observed to be abnormally small (approximately 4 KB) compared to its original 2 MB size.

Before you start

Before proceeding, locate the folder where the corrupted file is currently saved, as you will need to access the directory's version history features or local temporary files.

Solution 1Recommended

Restore a Previous Version from OneDrive or SharePoint

If your encrypted Excel file was synced to cloud storage, you can easily restore an earlier, uncorrupted version using the Version History feature.

A file size drop to 4 KB indicates that the actual data inside the workbook is entirely gone. In this severe state, repair tools cannot recreate missing data. The only viable solution is restoring the file from a previously synced cloud version.

Locate the File Online

Log in to your OneDrive or SharePoint account through a web browser and navigate to the folder containing your corrupted Excel file.

Access Version History

Right-click the corrupted Excel file and select 'Version history' from the context menu.

Select an Older Version

Browse the list of previous file versions. Look for a version saved prior to the corruption (ideally one that is close to the original 2 MB size).

Restore the File

Click the 'Restore' button next to the healthy version to replace the corrupted 4 KB file with the working copy.

Password Requirement: You will still need the original encryption password to open the restored version of the file.

Solution 2

Search for Local AutoRecover Files

Check Excel's built-in AutoRecover feature to see if a temporary backup was saved locally before the file became corrupted.

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Prevent Data Loss with WPS Office's Built-in Backup

While severely corrupted 4 KB files cannot be repaired, switching to WPS Office can help prevent such disasters. WPS Office is a free, lightweight Microsoft Office alternative offering powerful auto-backup and cloud syncing to keep your encrypted data safe.

1. Download the Software: Visit the official WPS website and click the download button to get WPS Office Free.
2. Install and Launch: Run the installer and launch WPS Spreadsheets once the installation is complete.
3. Open Your Files safely: Open your existing Excel workbooks directly; WPS automatically handles Microsoft formats and provides secure cloud backup options.

High compatibility with Microsoft Excel (.xlsx, .xls) and encrypted formatsBuilt-in automatic backup and cloud sync to prevent future data lossLightweight software that runs smoothly on almost any deviceFamiliar, easy-to-use interface for seamless migration from Microsoft Office

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Frequently Asked Questions

Why did my encrypted Excel file size drop to 4 KB?

When an Excel file size drastically drops to a few kilobytes (like 4 KB), it usually indicates that the internal data structure has been wiped out or severely corrupted. The 4 KB only contains basic file headers, meaning the actual spreadsheet data is missing.

Can third-party repair tools fix a 4 KB encrypted Excel file?

No. A file size of 4 KB means the actual data is no longer present within the file. Third-party repair tools cannot recover data that doesn't exist; they can only fix files where the data is still present but scrambled.

How can I prevent my password-protected Excel files from corrupting?

To minimize corruption risks, avoid abrupt system shutdowns, do not pull out USB drives while saving, and regularly save backups to cloud services like OneDrive, SharePoint, or WPS Cloud to utilize automatic version history.

Does Excel automatically backup encrypted files?

By default, Excel's AutoRecover attempts to work for encrypted files depending on your local settings. However, it is highly recommended to manually save extra copies or use cloud storage with version history for critical password-protected workbooks.

Document & File Issues