GetSerial

Option Explicit

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)
Const MAX_FILENAME_LEN = 256

Private Sub Command1_Click()
Label1.Caption = SerNum("C") 'C is the standard harddisk
End Sub

Public Function SerNum(Drive$) As Long
Dim No&, s As String * MAX_FILENAME_LEN
Call GetVolumeInformation(Drive + ":\", s, MAX_FILENAME_LEN, _
No, 0&, 0&, s, MAX_FILENAME_LEN)
SerNum = No
End Function