Sorry,

I did a bad thing. I just put part of the code. You should release all the COM objects when done with them in reverse order. That's every workbook, sheet, range etc. something like:

Private Sub btn1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn1.Click
Dim xlApp As Excel.Application
Dim xlSht As Excel.Worksheet
Dim xlRng As Excel.Range

Try
xlApp = New Excel.Application
xlApp.DisplayAlerts = False
xlApp.Workbooks.Open("c:\test.xls")
xlSht = xlApp.Sheets(1)
xlRng = xlSht.Cells(1, 1)
Textbox1.Text = xlRng.Value

Catch ex As Exception
Textbox1.Text &= ex.ToString
Finally
xlApp.Workbooks.Close()
ReleaseComObject(xlRng)
ReleaseComObject(xlSht)
ReleaseComObject(xlApp)
xlSht = Nothing
xlApp = Nothing
GC.Collect()
End Try
End Sub


Dan