If you have created an Amazon EC2 instance and are not being able to access it through SSH, dominant chance is that you have not configured a key-pair with your EC2 instance.
Following steps elaborate how to create and a key-pair with your EC2 instance:
- Goto EC2 tab, create a key-pair.
- Download key-pair and save it at a place from where you can easily access it.
- Create an EC2 instance with current key-pair. If you have already created an EC2 instance, you will need to terminate it and create a new one.
- Convert key-pair to private key using puttygen. This will generate a ppk file.
- Use putty ( or any secure shell app ) with your ppk file.