Declare Function WriteFile Lib "kernel32.dll" (ByVal hFile As Long, ByRef _
  lpBuffer As Any, ByVal nNumberOfBytesToWrite As Long, ByRef _
  lpNumberOfBytesWritten As Long, ByRef lpOverlapped As Long) As Long
 
Sub WriteSectorToDrive(buffer() As Byte)
'schreibt 512 Bytes (1 Sektor) von buffer()
    If CreateFileError Then
        ReadFileError = 1
        Exit Sub
    End If
 
    retwriteFile& = WriteFile(lngFileHandle, buffer(0), 512, BytesWrite&, 0&)
    If retReadFile& = 0 Then
        MsgBox "Readfile returns " & Str$(retReadFile&) & vbCrLf & "Read Error!"
        ReadFileError = 1
        Exit Sub
    End If
End Sub

lngFileHandle = CreateFile(FileName$, GENERIC_READ Or GENERIC_WRITE, _
  FILE_SHARE_READ Or FILE_SHARE_WRITE, ByVal 0, OPEN_EXISTING, _
  FILE_ATTRIBUTE_NORMAL, ByVal 0)

Private Sub Command6_Click()
Dim i As Integer
For i = 0 To 254
  puffer(i) = i
Next i
WriteSectorToDrive puffer()
End Sub