When you create Shared Service Provider, you can get the following error: Shared Service Provider Provisioning Failed: user can't be found. Shortly when you create SSP, the job will create a site collection for administration site of SSP and the job make the users who are site collection administrators of central administration as site collection administrators for the site collection of SSP. but when the site collection administrators of central administration are wrong, the job will failed. So to fix it, just do the following:
1. Go to central administration site collection and set the site collection administrators correctly.
2. Execute the following command: stsadm -o execadmsvcjobs .