I am trying to automate Word from a VB.net application but keep getting the error:
"Unable to cast COM object of type 'Microsoft.Office.Interop.Word.ApplicationClass' to interface type 'Microsoft.Office.Interop.Word._Application'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{00020970-0000-0000-C000-000000000046}' failed due to the following error: Library not registered. (Exception from HRESULT: 0x8002801D (TYPE_E_LIBNOTREGISTERED))."

I ran RegAsm to register Office.dll, Microsoft.Vbe.Interop.dll and Microsoft.Office.Interop.Word.dll successfully.

However, I continue to get this error when oWord.Visible = True attempts to execute.

Imports Word = Microsoft.Office.Interop.Word
Imports System.Runtime.InteropServices
 
Private Sub OpenWordDoc
       Dim oWord As Word.Application
        Dim wDoc As Word.Document
        Dim para1 As Word.Paragraph
        Dim strResult As String
 
        oWord = CreateObject("Word.Application")
        oWord.Visible = True
 
        wDoc = oWord.Documents.Add
        para1 = wDoc.Content.Paragraphs.Add
        para1.Range.Text = RepairCommentsTextBox.Text
 
 
        'para1 = wDoc.Content.Paragraphs.Add()
        'para1.Range.Text = RepairCommentsTextBox.Text
        'para1.Range.InsertParagraphAfter()
 
        wDoc.CheckSpelling()
 
        strResult = Microsoft.VisualBasic.Left(wDoc.Content.Text, Len(wDoc.Content) - 1)
        If Not RepairCommentsTextBox.Text = strResult Then
            RepairCommentsTextBox.Text = strResult
        End If
End Sub

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