BENTECH

Excel Security & Recovery: Manual Worksheet Password Removal

Master the OpenXML architecture of Microsoft Excel workbooks to safely remove forgotten worksheet passwords by editing underlying XML tags without external software.

This hands-on course provides detailed technical instructions on how modern Excel files are packaged and how worksheet protection is stored. Learners will discover how to convert Excel files into inspectable ZIP archives, navigate the internal directory structure, locate and purge the <sheetProtection> XML element, and rebuild an uncorrupted, fully editable spreadsheet.

Section 1: Archive Conversion and File System Preparation

Understand the file architecture of Excel workbooks and prepare the operating system for extension manipulation.

Lesson 1.1: Workbook Backup and File Extension Configuration

  • Worksheet protection read-only error behavior
  • Creating non-destructive workbook duplicates
  • Enabling file extensions in Windows File Explorer

When a worksheet is protected in Microsoft Excel, users cannot edit locked cells or format contents without knowing the protection password. Attempting to modify protected cells generates a warning message stating that the sheet is read-only. Because direct file manipulation carries a risk of syntax errors, best practice dictates duplicating the original workbook before making changes. Modern Excel files (.xlsx, .xlsm) are built on the OpenXML standard, meaning they are ZIP archives containing XML documents. To view and alter the file extension, Windows File Explorer must be configured to show extensions. This is accomplished by opening any folder, navigating to the View tab in the ribbon, and checking 'File name extensions'.

Practical work

  1. Create a duplicate copy of a macro-enabled or standard Excel workbook.
  2. Open Windows File Explorer, click the View tab, and toggle 'File name extensions' on.

Lesson 1.2: Archive Renaming and Extraction

  • Renaming workbook extensions to .zip
  • Handling Windows file extension warnings
  • Extracting the internal package hierarchy

Once file extensions are visible, right-click the target workbook and change the file extension from .xlsm or .xlsx to .zip. Windows will present a confirmation dialog warning that changing the extension might make the file unusable; confirm this prompt with 'Yes'. Once renamed, the file is treated as a standard compressed folder. Using Windows Extract tools or any archive utility, extract the archive contents to a dedicated folder on your desktop. The extracted directory exposes four core structural components: the '_rels' folder, 'docProps' folder, 'xl' folder, and '[Content_Types].xml'.

Practical work

  1. Rename the workbook file extension to .zip and accept the system warning prompt.
  2. Extract all files from the archive to a folder on your desktop and inspect the four root items.

Section 2: XML Modification, Repackaging, and Validation

Locate and excise sheet protection XML tags, recompress the package, and restore full workbook functionality.

Lesson 2.1: Locating and Excising the Sheet Protection Tag

  • Identifying the target worksheet XML
  • Editing XML with plain text editors
  • Removing the <sheetProtection> tag safely

Open the extracted folder and navigate into the 'xl' subdirectory, followed by 'worksheets'. In this directory, each worksheet corresponds to a numbered XML file (e.g., sheet1.xml, sheet2.xml). Open the XML file corresponding to the locked sheet using a plain text editor such as Notepad. Do not use a word processor like Microsoft Word, as rich text editors may inject unintended formatting characters that corrupt XML syntax. In Notepad, press Ctrl + F and search for 'protection'. Locate the tag beginning with '<sheetProtection' and ending with '/>'. This tag contains attributes such as the password hash and specific permission locks. Highlight and delete the entire tag from '<' to '/>', taking care not to delete preceding or subsequent tags. Save the file (Ctrl + S) and close Notepad.

Practical work

  1. Open the target sheet XML file inside xl/worksheets using Notepad.
  2. Use Ctrl + F to search for 'protection' and locate the entire <sheetProtection ... /> node.
  3. Delete the complete tag, save the file with Ctrl + S, and verify the remaining XML remains intact.

Lesson 2.2: Recompression, Extension Restoration, and Verification

  • Selecting package contents for recompression
  • Converting ZIP back to Excel extension
  • Verifying sheet unlock in Excel Review tab

To reconstruct the Excel workbook, navigate to the root of the extracted folder containing '_rels', 'docProps', 'xl', and '[Content_Types].xml'. Select all four items simultaneously. Crucially, do not compress the parent directory; compress only these four root contents by right-clicking and choosing 'Send to' > 'Compressed (zipped) folder'. Assign a name to the newly created zip file. Next, rename the file extension from .zip back to its original Excel extension (.xlsm for macro-enabled workbooks, or .xlsx for standard workbooks). Confirm the Windows prompt when prompted. Launch the newly renamed workbook in Microsoft Excel. Navigate to the Review tab. The ribbon will now display 'Protect Sheet' instead of 'Unprotect Sheet', indicating that sheet-level security has been eliminated and cells are immediately editable.

Practical work

  1. Select the four root package components and compress them into a new .zip archive.
  2. Rename the resulting .zip file back to .xlsm or .xlsx.
  3. Open the file in Microsoft Excel and verify that previously locked cells can be modified without a password.