How to auto launch an EC2 instance to another availability zone in AWS?

I'm newbie to AWS. I have an EC2 Windows instance where my server is running in one availability zone of a region.

My need is reliability of the instance if region/availability zone goes down. I know that snapshots or AMIs are a way of taking backup. Replication of instance to multiple availability zones also possible.

My Question?

1) what is the probability of an instance or region goes down?

2) Is there any way to auto launch of a running instance to another availability zone or to another region if the availability zone or region of my instance goes down?

3) Better way for reliability of instance?

All possible suggestions are welcome. Thanks In Advance.