You don't tell us how big the file is.

You might not be able to store it in the internal memory and read it reversed?

Anyhow you can read the file per line and write it to another file.

There must be something in the file which tells the date or year of a record.

If the file is sorted you can use a pretty simple and fast method like:

Imports System

Imports System.IO

Public Class testa

Public Shared Sub test()

Dim line As String

Dim reader As StreamReader = New StreamReader("C:\temp\input.txt")

Dim writer As StreamWriter = New StreamWriter("C:\temp\output.txt")

line = "start"

' Loop over each line in file, While line is Not Nothing.

Do While (Not line Is Nothing)

line = reader.ReadLine

If Mid(line, 1, 9) <= "something" Then ' Adjust

Else

writer.WriteLine(line)

End If

Loop

writer.Close()

reader.Close()

End Sub

End Class

Thanks

Gosta