A forgotten sheet password feels like a locked door, but on a modern .xlsx file there is no door. The file is a ZIP archive of XML parts, and sheet protection is a single element written inside one of them. Delete that element from a copy of your own file, and Excel opens it unprotected, with every formula and value intact.
This guide works because of how a modern Excel file is built. An .xlsx file is not a solid block of data; it is a ZIP container holding XML documents, one per sheet, plus shared parts. When you protect a sheet, Excel does not scramble anything. It writes a sheetProtection element into that sheet's XML, and on opening, Excel reads the element and enforces it. Remove the element and there is nothing left to enforce. The steps below do exactly that, on a copy, so your original stays untouched whatever happens.
Sheet protection was designed to prevent accidents, and its design shows it. Excel stores a hashed password inside the sheet's XML and checks what you type against that hash when you click Unprotect Sheet. But the cell values and formulas sit in the same file in plain, readable XML. Nothing about the protection touches them. That is why the honest description of sheet protection is a do not edit sign, and why removing the sign from your own file is quick, complete and safe for the data.
The same design covers workbook structure protection, which lives as a workbookProtection element in the file xl/workbook.xml. If your problem is that sheets cannot be added, deleted or renamed, that is the element to remove instead, using the same routine.
Do every step on a duplicate. Keep the original exactly as it is until the unprotected copy has been opened and checked.
Report - Copy.xlsx..xlsx to .zip, then open it with Windows Explorer or a tool like 7-Zip.xl, then worksheets. Each sheet is a file like sheet1.xml. Open the one for the protected sheet in a text editor such as Notepad.<sheetProtection and delete the whole element, from its opening bracket to its closing />..xlsx.Two errors cause almost every failure. The first is zipping the wrong level: if you extract everything and then zip the outer folder, the archive contains a folder inside it instead of the parts at the top level, and Excel reports the file as corrupt. The parts, including the xl folder and [Content_Types].xml, must sit at the root of the ZIP. Editing the XML inside the archive with 7-Zip avoids the problem entirely, because the structure never changes. The second error is a text editor that saves the XML with extra formatting or a changed encoding. Use a plain editor, change nothing except deleting the element, and save.
If Excel still offers to repair the file, do not save the repaired version over anything. Go back to the untouched original, make a fresh copy, and redo the edit more carefully. This is exactly why the copy-first rule exists.
Honesty matters here. This routine removes protection: sheet protection and workbook structure protection. It does nothing at all for a file that asks for a password before opening, because that file is encrypted and its XML is not sitting there to edit. If you rename an encrypted .xlsx to .zip, you will not find readable worksheets inside at all. That is a different problem with a different, harder answer, covered in the guide on forgotten file-open passwords. Also note the legacy format: an old .xls file is not a ZIP. Open it in Excel and save it as .xlsx first, then use this routine on the converted copy.
The video shows this recovery on a real file, step by step, including which password type it works on.
Watch Full VideoNo, when done carefully. The element contains only protection settings and the password hash. Your rows, values and formulas live in a separate part of the same XML and are not touched. The real risks are structural: zipping the folder at the wrong level, or an editor mangling the XML. Work on a copy, and verify the result by opening it and checking a few known values before relying on it.
Almost always the ZIP structure. When the parts were re-zipped, a folder ended up inside the archive, so Excel finds a folder where it expects the file parts at the root. The fix is to start again from the untouched original and either zip the contents at the correct level or edit the XML in place inside the archive with a tool like 7-Zip, which never disturbs the structure.
No. A file with an open password is encrypted; its contents are scrambled bytes, and there is no readable XML and no protection element to remove. The ZIP test is actually a quick way to tell the two locks apart: if you can browse worksheets inside the ZIP, it was protection. If you cannot, it is encryption, and only guessing the password can help.