Private Key Conversions

Convert OpenSSH private key to Putty ppk format:
Step 1:Download and run Puttygen.
Step 2:Select "Import Key" From "Conversions" menu.
Step 3:Type your passphrase if you have set them.
Step 4:Click "Save private key".

Convert Putty ppk format to OpenSSH format: 
Step 1:Select "Load private key"
Step 2:Select "Export OpenSSH key"

Convert Putty ppk format to ssh.com format:
Step 1:Select "Load private key"
Step 2:Select "Export ssh.com key"