Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
When a laptop's motherboard is replaced, Microsoft's activation servers register the device as a completely new computer. This is why you lost access to your pre-installed apps (like Word and PowerPoint), as OEM licenses are tied to the original hardware's specific digital signature. The most effective way to help her is to direct her to the official Microsoft Support website or the built-in Windows Get Help app to initiate a live chat or callback, advising her to keep her original purchase invoice and Lenovo repair documents on hand so the agent can manually authenticate and restore her software license.