HELP! EAP-TLS: how can I install a cert on a workstation so that it works for all users

Hi all, I can't find this information anywhere. I have looked for days. Can I create a client cert for a computer so that any user that logs in may use it automatically under Windows XP? I have successfully created a client.p12 with the FQDN of the workstation I am using, installed it and been authenticated by Freeradius. However when I log in to the computer under a different windows profile authentication fails. How should I create this file and where do I place this cert so that it's available for any user logging on? Please help me figure this out! Thanks! John