How can I restore unique hardware IDs after a failed HPE BIOS recovery?

It sounds like the machine was effectively given firmware data from another system, so some board-specific values may now be duplicated. The BIOS can contain the onboard NIC MAC addresses and system UUID or serial-related information. If you have a verified dump from this exact motherboard, compare it with the current contents and restore the missing identity fields. Do not edit random offsets without a board-specific layout or a known-good backup, because corrupting the descriptor or management-controller regions could make recovery harder.

Changing the MAC address in Windows can get networking working temporarily, but it does not repair the firmware identity and may not solve duplicate UUID or SMB-related problems. Once the hardware identifiers are corrected, remove any temporary NIC override, confirm each server has a unique name, SID-independent domain identity, UUID, and MAC address, then rejoin the affected machine to the domain if necessary. Also verify that the file-server shares and DNS records point to the correct host.

The exact HPE model matters. Many ProLiant systems have redundant BIOS ROMs and recovery features through the system ROM and iLO. Before manually programming anything else, check whether the backup ROM, iLO recovery process, or the model-specific system ROM recovery procedure can restore the board properly. HPE support may also be able to provide the correct platform-specific image.