Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

Dim fileReader As System.IO.StreamReader
fileReader = _
My.Computer.FileSystem.OpenTextFileReader("C:\\hpfr3740.log")
Dim stringReader As String
stringReader = fileReader.ReadLine()

Do While Not stringReader Is Nothing
RichTextBox1.AppendText(stringReader)
stringReader = fileReader.ReadLine()
Loop


End Sub
End Class 

Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim myText As String
Dim objStreamReader As System.IO.StreamReader
objStreamReader = New System.IO.StreamReader("C:\\hpfr3740.log")

myText = objStreamReader.ReadLine

Do While Not myText Is Nothing
RichTextBox1.AppendText(myText)
myText = objStreamReader.ReadLine
Loop

End Sub
End Class