How to make PuTTY NOT remember the passphrase?

Question

I imported an SSH key into PuTTY (creating a .ppk file). My SSH key uses a passphrase.

When I first logged in using that .ppk, PuTTY asked for my passphrase, but apparently, this passphrase is stored because it didn't ask me for the passphrase in the following connections.

I need to input the passphrase every time. How can I configure PuTTY to always ask for it?

This is the event log for the connection:

=~=~=~=~=~=~=~=~=~=~=~= PuTTY log 2019.08.01 11:47:20 =~=~=~=~=~=~=~=~=~=~=~=
Using username "gordo".
Authenticating with public key "imported-openssh-key" from agent
Last login: Thu Aug  1 10:46:13 2019 from ip-<ip_redacted>.ec2.internal
]0;gordo@ip-<ip_redacted>:~[gordo@<ip_redacted> ~]$ exit
logout

Answer 1

Authenticating with public key "imported-openssh-key" from agent

You have the key loaded into PuTTY authentication agent – Pageant. So it was not PuTTY that asked you for the passphrase, it was the Pageant.

The very purpose of the Pageant is to avoid the need to type the passphrase every time.

Remove the key from Pageant, if you actually want to type the passphrase every time. Pageant lives in Windows task bar tray. Its icon is an old desktop computer with a hat.