I'm assuming you mean you want to separate the lines in a notepad (text) document into an array of lines. Do you need to get the text from an open instance of notepad or is it sufficient to read the text from a file?
If you are reading from a file you can just do
Dim lines() As String = System.IO.File.ReadAllLines(filename)
If you already have a string that you want to separate you can do
Dim lines() As String = Split(text.Replace(vbCr, ""), vbLf)
If you do this instead of just
Dim lines() As String = Split(text, vbCrLf)
then you guarantee that the lines will be parsed whether the lines end with vbLf or vbCrLf.