When we download a private SSH key it gets downloaded in the .key (PEM) format but for authentication to login to our instance using PuTTY we need private key in the .ppk (PuTTY Private Key) format. To change private key format to use with PuTTY we need PuTTYgen which is PuTTY Key Generator application.

Download PuTTY Package file

PuTTY Package file comes with bundle of applications which includes PuTTYgen (for key generation), PuTTY (for connecting to the instance) and other utility applications.

Use PuTTYgen for private key format conversion

• From the Start menu search PuTTYgen and open it

• On the PuTTYgen application home page click on Load

• Select file type as All Files (*.*) and select path to the private key

• Select the private key which is shown in .key extension and click open

• A Notice pop-up will appear click OK

• In action pannel click on Save private key

• A Warning pop-up will appear click Yes

• To save enter file name without extension and click Save