Check Excel’s Document Recovery pane when reopening Excel
Go to File > Info > Manage Workbook > Recover Unsaved Workbooks
Look in the AutoRecover file location for temporary Excel files
Search your computer for files with .xlsb, .xlsx, or .tmp extensions
Open the Excel temp folder from the Run dialog using %temp%
Check the Recycle Bin for the missing file
Restore a previous version if File History or backup is enabled
Check OneDrive, SharePoint, or cloud sync version history if the file was stored there
Look for recent files in Excel’s Open > Recent list
Enable AutoRecover and set a shorter save interval for future files