How to unprotect an Excel-sheet without the password

Things aren’t quite as hopeless if you want to unprotect a Excel worksheet but no longer know the password. There is actually a trick for this. However, it involves file manipulation, and there’s no guarantee it will work with all current and future versions of Excel. Of course, we assume that you will only attempt this if you are authorized to do so. Step 1: Before performing any of the steps below, make a copy of the Excel-file in question. Carry out the following steps using the copied version, because if you make a mistake while modifying the file, you still have the unmodified original version and can start over. Step 2: Open the copy of the file with 7-Zip. The 7-Zip program comes preinstalled on Windows 10, so all you need to do is right-click on the file and select Open from the 7-Zip menu. If 7-Zip is not installed on your system, you can download it for free at 7-zip.org.
 Step 3: Open the xl folder inside 7-Zip.
Screenshot of Excel file opened with 7-Zip program
After unzipping the Excel-file in 7-Zip, you will see the document’s internal file structure.
Step 4: Now open the worksheets folder.
Screenshot of Excel file, “xl” directory, unzipped with 7-Zip
In the “xl” directory, you’ll find the “worksheets” folder, i.e., the individual worksheets of the Excel-file.
Step 5: Now you can view one or more files like sheet1.xml, sheet2.xml, etc. These files correspond to the individual worksheets of your Excel-file. Let’s assume your protected worksheet corresponds to the sheet1.xml file. If you have more than one worksheet, you may need to determine which Excel-sheet you need to remove the password protection from. Now, edit the file using a text editor. The easiest way to do this is to right-click the file in 7-Zip and then click on Edit. Alternatively, you can select it and press the [F4] key.
Screenshot of the Excel file, directory “xl\worksheets”, opened in the program 7-Zip, with context menu
Via the context menu (accessible with the right mouse button) you can open and edit the individual worksheets in XML format.
Step 6: The file is now open in the Windows editor. As you can see, XML files are not exactly reader-friendly because they are usually not intended for human eyes. Make sure that text wrap is enabled in the text editor (Format > Wrap Text) so that the text does not scroll out sideways. Now, look for the string <sheetProtection in the text and select all text up to the closing />:
The XML file of a worksheet opened in the Windows editor with the sheet protection entry marked
In the XML-code of the worksheet, you can find the entry for the sheet protection and remove it directly.
This XML-entry represents the sheet protection. Step 7: Delete the entry you have selected, starting from <sheetProtection all the way up to the next />. Be careful not to delete anything else so as not to damage the structure of the XML file. Step 8: Close the text editor. To save the changes, you need to confirm them. Since you opened the file in 7-Zip, 7-Zip will now ask: “The file sheet1.xml has been changed. Should it be updated in the archive?” Confirm the changes so that they are applied to the Excel file and close 7-Zip. Result: You can now open the modified copy of the file in Excel. You will find that the sheet protection has been removed and the worksheet can now be edited again. While this method lets you remove Excel sheet protection, you cannot find out which password was previously used. As shown in the text editor, the password is stored internally using hash values, making it impossible to be worked out.
! Note
Changing an Office file’s source code should only be attempted as a last resort. It is important to create backup copies in case the file is destroyed. Even if, at first glance, the change was successful, it is best not to continue using the Excel file in question, but to set it up again if necessary. Please also remember that you are liable for any damage that results from changes you have made to the source code.