Ok, when you have placed a textbox on your form.
Set by the properties of the textbox by Multiline = True
And place this code under the command or whatever event. 
Code:
Dim sData As String
Dim iFile As Integer
iFile = FreeFile
' place your own directory and file here
' if the file does not exist your will get
' error 53 "file not found"
Open "C:\File.Txt" For Input As iFile
While Not EOF(iFile)
' read the all the lines here
Line Input #iFile, sData
' place the line in the textbox and ending with a
' Chr(13) & Chr(10) = enter
Text1.Text = Text1.Text & sData & Chr(13) & Chr(10)
Wend
Close iFile
I hope this will work for you.. 
-Kayoca Mortation