Bookmark this! aka.ms/AzureMFA
As I make resources for my customers and internal community members at Microsoft, then I like to repurpose these resources for the rest of the world to enjoy as well! As I will be doing some writing on Azure MFA, I will make this blog as an account of all of my research and reference materials that can also be useful for our customers and partners in our ecosystem. I hope they are useful to you with a simple URL to remember.
Extending Multi-Factor AuthN Provider
Top level doc containing many sub links!
Manage Risk with Additional Multi-Factor Authentication for Sensitive Applications
Getting started with Windows Azure Multi-Factor Authentication
Good blog to walk you through setting up Microsoft Azure Multi-Factor Authentication
GOT Questions? We got a DL
To Re-Activate your MFA Server
Delete "C:\Program Files\Multi-Factor Authentication Server\Data\licenseKey", stop the multifactor service, then start the service again you should be able to re-activate next time you start the MFA admin app.