A workbook that will not open usually fails in one of three ways: Excel reports the file format is wrong, it offers to repair and then repairs nothing, or it opens to a blank or partially empty sheet. Each has a different cause and a different first move.

Try these in order. The order matters — step 6 is destructive, and steps 1 to 5 are not.

1. Copy the file somewhere local first

If the workbook lives on a network share, a synced folder or a USB stick, copy it to C:\ before doing anything. Half of all “corrupted file” reports are actually interrupted reads: the bytes on disk are fine, the read path was not.

Open the copy. If it opens, the file was never damaged — the network path or the drive is the problem.

2. Unblock it

Files that arrived by email or download carry a Zone.Identifier mark, and Excel may refuse them silently.

Right-click the file → Properties → tick Unblock at the bottom → OK. Try again.

This fixes more downloaded workbooks than any other single step.

3. Open and Repair

This is Microsoft’s built-in repair, and it is genuinely useful about half the time.

File → Open → Browse, select the file, then click the small arrow beside the Open button and choose Open and Repair. Choose Repair first; if that fails, reopen the original and choose Extract Data instead.

Extract Data keeps values and formulas and throws away formatting, charts and images. That trade is often the right one — but only do it on a copy, never the original.

4. Open it in Excel Online or Google Sheets

Upload the broken file to Excel for the web (or Google Sheets) and open it there. These renderers are far more forgiving about damaged internal XML.

If it opens online, you have two options: use it as-is, or download it again as a fresh .xlsx. The re-exported file is usually clean — but check that formulas and number formats survived before deleting the original.

5. Look at what kind of file it actually is

Rename a copy from book.xlsx to book.zip and try to open it with Windows Explorer (or any archiver).

  • It opens as a folder → the file is a valid Office package and the damage is inside it. Recoverable, usually.
  • “The archive is invalid” → the file is truncated or overwritten. This is much more serious.

A truncated file is the case where a specialist is worth paying: the data may still be sitting in the file, past the point where Excel stops reading.

6. Do not re-save it. This is the step that destroys files

The instinct when a file misbehaves is to open it in something else and save. Every successful save from a “file fixer” tool, an old Office version, or a half-broken viewer overwrites the damaged structures that a proper repair depends on.

Once a file has been re-saved twice by different programs, the original internal references are usually gone for good.

Keep the broken original untouched. Work on copies only.

7. Check the recovery folder before you touch anything

Excel keeps crash leftovers in:

%AppData%\Microsoft\Excel\
%LocalAppData%\Microsoft\Office\UnsavedFiles\

Look for .xlsb, .xar or random-named temp files matching the date of the failure. A file recovered from here is worth far more than a repaired one, because it never had the damage.

When to stop and hand it over

If the file does not open with Open and Repair, does not open online, and the ZIP test says the archive is invalid, further attempts are mostly risk. That is the point to send it to someone who can read the file structure directly.

FAQ

Does Open and Repair ever make the file worse?

It can, and this is the part nobody warns you about. Open and Repair rewrites the parts it manages to parse, in the same file. If it fails, you have a file that is both broken and partially rewritten. Run it on a copy, keep the original untouched, and stop after two attempts.

The workbook opens but one sheet is missing. Is the data gone?

Usually not. A missing tab is often a sheet that was set to very hidden by a macro, or a broken relationship entry in xl/workbook.xml. In the first case: Alt+F11, open the Immediate pane, and run ThisWorkbook.Sheets("SheetName").Visible = -1. In the second, the sheet XML is still in the archive and can be reassembled — the same structural repair described in the “some content” error walkthrough.

Can a file be recovered after I already saved over it?

Sometimes, from a previous version in OneDrive, or from the copy Excel leaves in %Temp% while a workbook is open. Both are worth checking before giving up, and both need to be done before Excel is reopened and overwrites them again.

If none of these bring it back, that is the point where a manual repair is worth the money — see what an engineer actually does with the file.

Stuck at step 5 or 6? Email the file, unmodified, to help@easyofficefix.com with the exact error text. You will get an assessment and a flat price before any work starts — and an honest "not recoverable" if that is the answer.