How do you set private keys in putty enmasse in Windows?

In line with this question…if you have a large number of hosts, and a large number of users who service these hosts, how do you set the private keys for these hosts enmasse across the users who connect to them with putty? So that you don’t have to risk the ‘trust of first use’ attacks.

I’m sure it probably has something to do with putty agent, but I’m uncertain what needs to be done.