Re: Pageant - couldn't load this key (unable to open file)
Please post a screenshot showing the configuration (preferences), PuTTY error message and Task Manager on the Details tab with Command line column for the Pageant visible.
Before posting, please read how to report bug or request support effectively.
Bug reports without an attached log file are usually useless.
"C:\Program Files (x86)\PuTTY\pageant.exe" C:\Users\my.user\.ssh\id_rsa.ppk -c "C:\Program Files (x86)\SuperPutty\SuperPutty.exe" !U@!@