Help with Tethered Shooting with 20D ?!?!?!?

Hello,
I am seeking instructions/pointers/​help using a 20D tethered to a computer for taking portraits at a family event. Having a real screen to check the portraits I'll be shooting to document our Family Reunion would be Great! My experiments to date have left my camera 'seemingly' unrecognized for capturing, but my potn search seems to directly say it's an available feature with a 20D. HELP!
Richard in Michigan

EOS 20D
Mac Mini G4 10.4.11
1gig 40gig 320gig dvdr etc etc

PC laptop running xp available for use
if need be.
(But I'm a Mac-O-Phile in my Heart).

Try updating the software, I think remember reading something about this in an older version.

HiYa,
I downloaded the latest updater/installer and hope it will help sort things out. I once did 'tethered shooting' experiments with my ancient DCS-520 (eos-1n modified to dig by Kodak) and found it a very nifty feature, but one I never had a need to use before now in 'real' life.
Richard