Hi Kinji Chiang,
the message "Windows License valid for 90 days" usually appears when a trial version of Windows 10 Enterprise is installed on a device. This version of Windows is designed for evaluation purposes and is valid for 90 days. After the 90-day period, the device will need to be activated with a valid license key to continue using Windows.
If your device is showing as activated in the Windows Activation settings, it is possible that the license key used to activate Windows is a volume license key that is valid for a limited time. In this case, you will need to obtain a new license key to renew the license.
To obtain a new license key, you can contact Microsoft support or your organization's IT department if you are using a volume license key. They will be able to provide you with a new key to activate Windows.
Best regards,
Lei