I have some private keys which I use to connect to few remote servers. In Windows managing SSH keys with Pagent is easy but loading a few keys everytime after reboot is annoying task. For luck Pagent has ability to load multiple ssh keys when it start up. The easiest method is to make shortcut in Startup program directory to Pagent with some additional params. Just like this:

The goal is to edit "Target" field with path to our private keys, ex:

Target: D:\SSH\pageant.exe d:\SSH\private.ppk d:\SSH\deployment_keys\private.ppk

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Also we can start Pagent from windows -> start -> run dialog with same params, ex:

D:\SSH\pageant.exe d:\SSH\private.ppk d:\SSH\0config\private.ppk