Если его C #, то
string myguid = Guid.NewGuid.ToString;
Если его доступ, то
Private Declare Function CreateGuid Lib "OLE32.DLL" (pGuid As GUID) As Long
Private Declare Function StringFromGUID2 Lib "OLE32.DLL" (pGuid As GUID, ByVal PointerToString As Long, ByVal MaxLength As Long) As Long
Private Type GUID
Guid1 As Long
Guid2 As Integer
Guid3 As Integer
Guid4(0 To 7) As Byte
End Type
Public Function CreateGUIDKey() As String
Const GUID_OK As Long = 0
Const GUID_LENGTH As Long = 38
Dim udtGUID As GUID
Dim FormattedGUID As String
Dim Result As Long
Result = CreateGuid(udtGUID)
If Result = GUID_OK Then
FormattedGUID = String$(GUID_LENGTH, 0)
StringFromGUID2 udtGUID, StrPtr(FormattedGUID), GUID_LENGTH + 1
Else
FormattedGUID = ""
End If
CreateGUIDKey = FormattedGUID
End Function