Step 1. Install PuTTY.

Step 2. Specify the hostname or Public IPof your machine in hostname column.

Step 3. In the Category panel, expand Connection, expand, and then select Auth.

Step 4. Click on Browse.

Step 5. Select the .ppk file that you generated for your key pair, and then click Open.

Step 6. Click YES. A window opens and you are connected to your instance.

Now you are successfully Login in your Amazon EC2 Instance.