To install FIM portal, the setup needs to run under SharePoint Farm administrator account.

What is it with Microsoft and unintuitive setup error messages? When attempting to install the FIM Service and Portal component of Microsoft Forefront Identity Manager 2010, I received the following error message.

"To install FIM portal, the setup needs to run under SharePoint Farm administrator account with at least Open permission that allows users to open a Web site, list, or folder in order to access items inside that container. Please make sure you are a SharePoint Farm administrator with Open permission then click "Retry". Click "Cancel" to abort setup."

The problem? I was not in the SharePoint Site collection administrators group. To add yourself to this group, open Central Administration (Start > Administrative Tools > SharePoint 3.0 Central Administration), click Application Management, then Site collection administrators. Change the Primary Site Collection Administrator to the account used to install FIM.

Links
Installation Error while configuring FIM Service & Portal, Microsoft TechNet