Where to place a client.p12 to use as a "computer certificate" under windows XP/sp2?

Hi all, Hopefully an easy one. I want to use certificates for some of the computers on the domain. I want the cert to be available for any user of the computer. I am not sure where to put it though. I've successfully installed a client.p12 under an individual profile but I need this to be available to everybody. I opened the certificate management console using certmgr.msc and I am looking around trying to figure out where this thing should go. Any ideas? Thanks! John