Operation failed, QueryInterface call on the COM component for the interface with IID failed due to Library not registered

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
using Excel = Microsoft.Office.Interop.Excel;

namespace GridComplete
{
    public partial class Form1 : Form
    {
        private static Excel.Workbook MyBook;
        private static Excel.Application MyApp;
        private static Excel.Worksheet MySheet;

        private void bRun_Click(object sender, EventArgs e)
        {
            MyApp = new Excel.Application();
            MyApp.Visible = false;
            MyBook = MyApp.Workbooks.Open(tbFile1);
            MySheet = (Excel.Worksheet)MyBook.Sheets[1];

        }

    }
}

On the line that sets MyApp.Visible to false, I get the following unhandled exception:

An unhandled exception of type 'System.InvalidCastException' occurred in GridComplete.exe

Additional information: Unable to cast COM object of type 'Microsoft.Office.Interop.Excel.ApplicationClass' to interface type 'Microsoft.Office.Interop.Excel._Application'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{000208D5-0000-0000-C000-000000000046}' failed due to the following error: Library not registered. (Exception from HRESULT: 0x8002801D (TYPE_E_LIBNOTREGISTERED)).

** I can't seem to figure what's going on. I tried to delete keys from the registry and rerun. That didn't work. I also fully uninstalled Microsoft Office, then reinstalled. I'm not sure what else to do to fix this issue.

It's possible that you don't have specified version of Microsoft Excel installed on computer where you running that code. Or it's installation broken. Try to re-install Office