For upgrading a non-Linux Kubernetes cluster, the correct installer type is Helm, since Helm charts are the supported method for deploying and managing Cortex XDR agents in Kubernetes environments.

During Cortex XSIAM tenant activation, data at rest is configured with AES 128 encryption by selecting "BYOK" (Bring Your Own Key) under the Advanced → Encryption Method option and following the wizard's instructions. This ensures secure key management and compliance with encryption standards.