from web site
You'll use the availability key to migrate to a new Data Encryption Policy with new keys provisioned by you. This prevents the computer from going into recovery mode. When Startup Repair is launched automatically due to boot failures, it will only execute operating system and driver file repairs, provided that the boot logs or any available crash dump point to a specific corrupted file.
Now you can protect yourself and backup your keys! Now even easier and faster to use in your daily design activities thanks to the improved user interface. The product key is located on the Certificate of Authenticity.
Service encryption with Customer Key for Office 365 FAQ - For issue type, select Subscription management, then select the applicable support plan and click Request for cancelation of a subscription.