Remove or Reset Password of Encrypted Workbook in C#, VB.NET

Using Spire.XLS, the password of an encrypted workbook can be removed or modified in case you know the open password. This article presents how to load a password protected Excel workbook, remove the protection or reset the password and then save the changes to the original file.

Step 1: Initialize an instance of Workbook class.

Workbook wb = new Workbook();

Step 2: Specify the open password and then load the encrypted Excel file.

wb.OpenPassword = "oldpassword";
wb.LoadFromFile(@"C:\Users\Administrator\Desktop\Encrypted.xlsx");

Step 3: Remove the password protection with UnProtect() method or reset the password by Protect() method.

//unprotect workbook
wb.UnProtect();

//reset password
wb.Protect("newpassword");

Step 4: Save the changes to file.

wb.SaveToFile(@"C:\Users\Administrator\Desktop\Encrypted.xlsx, ExcelVersion.Version2010");

Full Code:

[C#]

using Spire.Xls;
namespace RemovePassword
{
    class Program
    {

        static void Main(string[] args)
        {
            Workbook wb = new Workbook();
            wb.OpenPassword = "oldpassword";
            wb.LoadFromFile(@"C:\Users\Administrator\Desktop\Encrypted.xlsx");

            ////unprotect workbook
            //wb.UnProtect();
            //reset password
            wb.Protect("newpassword");
            wb.SaveToFile(@"C:\Users\Administrator\Desktop\Encrypted.xlsx", ExcelVersion.Version2010); 
        }
    }
}

[VB.NET]

Imports Spire.Xls
Namespace RemovePassword
	Class Program

		Private Shared Sub Main(args As String())
			Dim wb As New Workbook()
			wb.OpenPassword = "oldpassword"
			wb.LoadFromFile("C:\Users\Administrator\Desktop\Encrypted.xlsx")

			'''/unprotect workbook
			'wb.UnProtect();
			'reset password
			wb.Protect("newpassword")
			wb.SaveToFile("C:\Users\Administrator\Desktop\Encrypted.xlsx", ExcelVersion.Version2010)
		End Sub
	End Class
End Namespace

Remove or Reset Password of Encrypted Workbook in C#, VB.NET

See Also