The following sections you can find how to open and edit an Excel 2007 worksheet through VB.NET 2005. For open or edit an Excel 2007 worksheet in VB.NET 2005 , you have to add the Microsoft Excel 12.0 Object Library in you project.
From the following pictures to show how to add Excel reference library in your project.
1. Create a new project and add a button to the Form.
Select reference dialouge from Project menu

Select Microsoft Excel 12.0 Object Library and click OK button

Now you can start coding to open or read from Excel file and edit cells.
Imports Excel = Microsoft.Office.Interop.Excel
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles Button1.Click
Dim xlApp As Excel.Application
Dim xlWorkBook As Excel.Workbook
Dim xlWorkSheet As Excel.Worksheet
xlApp = New Excel.ApplicationClass
xlWorkBook = xlApp.Workbooks.Open("c:\test1.xlsx")
xlWorkSheet = xlWorkBook.Worksheets("sheet1")
'display the cells value B2
MsgBox(xlWorkSheet.Cells(2, 2).value)
'edit the cell with new value
xlWorkSheet.Cells(2, 2) = "http://vb.net-informations.com"
xlWorkBook.Close()
xlApp.Quit()
releaseObject(xlApp)
releaseObject(xlWorkBook)
releaseObject(xlWorkSheet)
End Sub
Private Sub releaseObject(ByVal obj As Object)
Try
System.Runtime.InteropServices.Marshal.ReleaseComObject(obj)
obj = Nothing
Catch ex As Exception
obj = Nothing
Finally
GC.Collect()
End Try
End Sub
End Class