Dim i As Long
Dim Arch As String
Dim Buffer as string
Arch = "C:\stub.log"
Buffer = Space$(25000)
   
    Open Arch For Binary Access Read As #1
     
    For i = 1 To FileLen(Arch) / 25000 'hacemos la division de las veces que tendra que leer y enviar
    Get #1, , Buffer 'leemos
    Winsock_server.SendData "archi" & vbParseData & Buffer
    DoEvents
    
    If FileLen(Arch) - Loc(1) <= 25000 Then 'como el for no utiliza los  decimales enviamos los restos
    Buffer = Space$(FileLen(Arch) - Loc(1)) 'redimensianamos la variable con el num de bites que faltan
    Get #1, , Buffer 'leemos
    Winsock_server.SendData "archi" & vbParseData & Buffer
    DoEvents
    End If
    Next i

    Winsock_server.SendData "fin"
    Close #1

Option Explicit

Private Type FileInfo
  Filename      As String
  FileSize      As Long
  TotalPieces   As Long
  BytesPerPiece As Long
  ByteRemaining As Long
End Type

Private Function ParseFile(Filename As String, BytesPerPiece As Long) As FileInfo
  With ParseFile
    .Filename = Filename
    .FileSize = FileLen(Filename)
    .TotalPieces = .FileSize \ BytesPerPiece
    .BytesPerPiece = BytesPerPiece
    .ByteRemaining = .FileSize Mod .ByteRemaining
  End With
End Function

Private Function CropFile(FileSpec As FileInfo) As Single
        Dim hFile%, snTime!
        Dim sData$, i&

  snTime = Timer
  
  With FileSpec
    hFile = FreeFile
    
    Open .Filename For Binary Lock Read Write As #hFile
    
    sData = String$(.BytesPerPiece, 0)
    
    For i = 1 To .TotalPieces
      If i < .TotalPieces Then
        Get #hFile, , sData
      Else
        sData = String$(.ByteRemaining, 0)
        
        Get #hFile, , sData
      End If
      
      'Luego acá se enviarían los datos.
      '
    Next
  End With
End Function

Tam = 1024
Trozos = FileLen(Arch) / Tam
Falta = FileLen(Arch) Mod Falta

If Falta > 0 Then Trozos = Trozos + 1