After closing Excel without saving, first preserve the last saved workbook and identify what is missing. Do not overwrite it with the first recovery candidate simply because that candidate has a recent timestamp.

This guide covers desktop Excel for Windows. Recovery availability depends on what Excel saved and whether AutoRecover was enabled. Microsoft describes AutoRecovery as a fallback rather than a substitute for saving the workbook regularly.

Look in the route that matches the file

For a workbook previously saved, open it and inspect File, Info, Manage Workbook for a version labelled as closed without saving. Microsoft’s Restore action replaces the previously saved version, so preserve that saved file before committing to restoration.

For a workbook that was never saved, use the Recover Unsaved Workbooks command available from the file-management controls under File, Info. Open an available candidate and use Save As to give the recovered file a deliberate name and location.

If no candidate is available, do not infer that enabling AutoRecover now will recreate past work. Check any independent backup or separately saved copy, and record the last known saved state before deciding what needs reconstruction.

Verify the recovered content

Compare the candidate with the saved workbook or your notes. Inspect the sheet edited most recently, the last several entered rows and any formulas changed during the lost session. A recovered file can contain only part of that work.

Save useful recovered content under a new name while you reconcile it. Confirm formulas, sheet names and important totals before treating the candidate as the new working version. Retain the earlier file until the comparison is complete.

Afterwards, inspect File, Options, Save and the AutoRecover interval for future work. Continue using normal Save and a separate backup plan. Recovery settings reduce some exposure to interruption, but the acceptance check is still whether the actual file contains the work you need.

References: Microsoft: recovering earlier Office files, Microsoft: saving and AutoRecovery.