Sacado de Area Visual Basic hace tiempo
Esto fue sacado hace algun tiempo de Area Visual Basic
Espero te sirva
PepeRou
Private Declare Function GetVolumeInformation& Lib "kernel32" Alias "GetVolumeInformationA" _
(ByVal lpRootPathName As String, ByVal pVolumeNameBuffer As String, ByVal nVolumeNameSize _
As Long, lpVolumeSerialNumber As Long, lpMaximumComponentLength As Long, lpFileSystemFlags _
As Long, ByVal lpFileSystemNameBuffer As String, ByVal nFileSystemNameSize As Long)
Private Sub Form_Load()
Dim cad1 As String * 256
Dim cad2 As String * 256
Dim numSerie As Long
Dim longitud As Long
Dim flag As Long
unidad = "C:\"
Call GetVolumeInformation(unidad, cad1, 256, numSerie, longitud, flag, cad2, 256)
MsgBox "El Nº de serie de la unidad " & unidad & " es " & numSerie
End Sub