I need to install the FIM password reset client add-ins on to computers that already have a 3rd party GINA installed (the application is called Pharos). By default, when I install the FIM add-ins, the Pharos GINA is just replaced by the FIM GINA. This is not acceptable to the client. What are my options? FIM is only being deployed for password reset (for 30000 users), so it would be a shame if this blocked it.

SSPR client doesn't support existing GINA plugin on XP. The GINA architecture makes it quite impossible to do soThe FIM Password Reset Blog http://blogs.technet.com/aho/

Is there any way to remove the GINA bits, but still be able to use the FIM portal for registration? And maybe even still be able to do password reset by logging in to a well-known "kiosk" account.

nope, but on the other hand, nothing prevents you from switching the GINA back to your custom GINA after installing the FIM Client... afterall, it's just registry... but of course, this approach is not recommended by microsoft

What's the registry key(s)?

http://msdn.microsoft.com/en-us/magazine/cc163803.aspx#S9