File Corruption & Recovery

How to Recover a Lost or Corrupted Excel File After Solver Freezes

Camila Milosovich Oct 7, 2026 871 views

Question details

The user needs to recover unsaved data and restore access to a corrupted Excel workbook that was forcibly closed during a Solver add-in freeze.

How to Recover a Lost or Corrupted Excel File After Solver Freezes

Product: Microsoft Excel
Device & OS: not provided
Scenario: Microsoft Excel became unresponsive and froze while the Solver add-in was running, requiring a forced application closure.
Observed behavior: Upon reopening the application, much of the recent work was missing, and the auto-recovered workbook could not be opened due to file corruption.

Before you start

Before attempting any repair methods, create a backup copy of the corrupted file and save it to your desktop. Verify that the file extension (such as .xlsx) is correct, and avoid manually renaming the extension to .xls as this does not change the actual file format and can cause further corruption.

Solution 1Recommended

Use Excel's Built-in Open and Repair Feature

Microsoft Excel includes a built-in repair utility specifically designed to fix damaged workbooks when standard opening methods fail.

This tool evaluates the workbook's underlying structure and attempts to repair any corruption that prevents the file from opening normally.

Open Excel and access the Open menu

Launch Microsoft Excel, click on the 'File' tab in the top-left corner, and select 'Open'.

Locate the corrupted file

Click 'Browse' and navigate to the folder where your corrupted workbook is stored. Click the file once to select it without opening it.

Select Open and Repair

Click the small arrow next to the 'Open' button at the bottom of the dialog box, and choose 'Open and Repair' from the dropdown menu.

Attempt to repair the workbook

Click 'Repair' in the prompt that appears to recover as much data as possible. If this fails to work, repeat the process but choose 'Extract Data' instead to pull raw values and formulas.

Use Excel's Built-in Open and Repair Feature

Pro Tip: If you are forced to use the 'Extract Data' option, your workbook's formatting will be lost, but your critical raw data and calculated values can be successfully salvaged.

Solution 2

Retrieve Unsaved Changes from AutoRecover

If the file is too damaged to repair, you can search for a temporary version saved automatically by Excel shortly before the freeze.

Solution 3

Restore a Previous Version via Cloud Version History

If you were saving your work to OneDrive or SharePoint, the cloud automatically keeps a detailed history of your previously synced versions.

Free Microsoft Office alternative

Prevent Data Loss with WPS Office's Smart Backup

If Microsoft Excel frequently freezes or crashes during heavy processing tasks, consider switching to WPS Office. It provides a lightweight, highly stable environment with an advanced Auto-Backup system to ensure your complex data and formulas are never lost during an unexpected freeze.

1. Download and Install WPS Office: Visit the official WPS website to download the free installation package for your operating system.
2. Open Your Existing Spreadsheets: Launch WPS Spreadsheet and easily open all your existing Microsoft Excel formats directly without any conversion needed.
3. Enable Smart Local Backup: Go to 'Menu' > 'Settings' > 'Backup Settings' to customize your auto-recovery intervals and ensure maximum data security.

Seamlessly compatible with Microsoft Excel (.xlsx, .xls, .csv) formatsAdvanced Auto-Backup system ensures quick file recovery after unexpected system crashesLightweight architecture handles complex calculations and heavy datasets smoothlyFree to download with a familiar user interface that requires zero learning curve

microsoft office alternative - wps office

Frequently Asked Questions

Can I fix a corrupted Excel file by renaming the .xlsx extension to .xls?

No. Simply renaming the file extension in File Explorer does not convert the underlying file format. Doing so can cause file structure mismatches and further reading errors. If you need a different format, you must open the file and use the 'Save As' function.

Where are Excel AutoRecover files saved on Windows by default?

By default, Excel saves unsaved AutoRecover files in the hidden directory 'C:\Users\[YourUsername]\AppData\Local\Microsoft\Office\UnsavedFiles'. You can access this folder directly via File Explorer or by using the 'Recover Unsaved Workbooks' option within Excel.

Why did Excel freeze when I was running Solver?

The Solver add-in runs complex iterative mathematical models that consume significant CPU and RAM resources. If your dataset is excessively large, constraints are poorly defined resulting in infinite loops, or system memory is low, Excel may become unresponsive and freeze.

What is the difference between 'Repair' and 'Extract Data' when opening a damaged file?

The 'Repair' option attempts to fix the corrupted structure of the workbook to open it exactly as it was. If structural damage is too severe, the 'Extract Data' option is used as a fallback to strip away all formatting and retrieve only the raw values and underlying formulas to minimize permanent data loss.

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