When you Replaced a HDD, or Re-installed the System Software
As the System Fingerprint does not change, you can reactivate IPDS with the same license file as the one used for the last activation. If the license file is lost, log in to the certificate site with the same EID as the one used for the last activation, and then download the license file again.
When you Replaced the Motherboard
As the System Fingerprint changes, you cannot reactivate IPDS with the same license file as the one used for the last activation. Activate IPDS with a new System Fingerprint and EID.