The new laptop nowadays usually don’t come with LAN ports, you may had an issue when trying to image multiple laptops with same USB to Ethernet Adapter.

Beginning with SCCM 1610, you can provide a list of hardware IDs that SCCM will ignore when using PXE boot and client registration. You can now exclude the MAC address and SMBIOS GUID in the console so that same adapters can easily be reused.

1. In the SCCM console, go to Administration / Site Configuration / Sites
2. On the top ribbon, click Hierarchy Settings
3. In the Client Approval and Conflicting Records tab
4. In the Duplicate hardware identifiers section, click Add and enter your MAC Address or SMBIOS GUID to exclude