Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        If PictureBox1.Image Is Nothing = False Then
            PictureBox1.Image.Dispose()
            PictureBox1.Image = Nothing
        End If
End Sub

If File.Exists(editfoto.text) Then
         Dim img As Image = Image.FromFile(editfoto.text)
         PictureBox1.Image = img.GetThumbnailImage( 32 ,  32 , Nothing, Nothing)
Else
         If PictureBox1.Image Is Nothing = False Then
             PictureBox1.Image.Dispose()
             PictureBox1.Image = Nothing
         End If
End If