[RESOLVED] Trouble closing EXCEL.exe COM instances

[VB.NETGAL]

Hello VB world!

This is my first post so forgive me if I don't supply enough information to my problem first time round. I'm still very much in the learning stage meaning that I have a general understanding of most of my code and part of it is made up from google searches to get me where I am with a small reporting application I'm building.

I have a function which I call below which initializes a new instance of EXCEL.exe in task manager. I'm having trouble disposing of this instance at the end of my function.

If I use

excelApplication.Quit()
        Marshal.ReleaseComObject(excelApplication)

right after I initialize the instance then it gets rid of it no problem. However at the end of my function it is not working. I have done a bit of searching on google before I came here and it basically says I have to release all instances of the com object but I can't work out what they are or if there is a better way to do it or find out. Hoping this is an easy one for someone else; it's been driving me mad for about 3 hours :O

Dim excelApplication As New excel.Application




        Dim fileInfo1 As New System.IO.FileInfo(XLSXFile)
        If fileInfo1.Exists Then
            SetAttr(XLSXFile, vbNormal)
            fileInfo1.Delete()
        End If

        Dim fxml As New System.IO.FileInfo(XMLFile)
        If fxml.Exists Then
            excelApplication.Workbooks.Open(XMLFile)
            excelApplication.Workbooks.Item(1).CheckCompatibility = True
            excelApplication.DisplayAlerts = False
            excelApplication.Workbooks.Item(1).SaveAs(XLSXFile, excel.XlFileFormat.xlWorkbookDefault)
            excelApplication.DisplayAlerts = False
            excelApplication.Workbooks.Close()
            SetAttr(XMLFile, vbNormal)
            fxml.Delete()

            'Else
            '    MessageBox.Show("XML File does not exists")
        End If

        Dim fileInfo2 As New System.IO.FileInfo(XLSXFile)
        If fileInfo2.Exists Then
            SetAttr(XLSXFile, FileAttribute.Normal)
        End If



        excelApplication.Quit()
        Marshal.ReleaseComObject(excelApplication)

Edit: The function takes an XML document and converts it to an XLSX document