Ok now i've done it.

I selected a figures left hand then selected Figure-Set figure parent chose the hand of a different figure. 

How do I undo this now??

Just go back and re-do it.  Make sure the figure you want to parent to is the right one, is all.  Pretty simple.

Sorry perhaps i was unclear.  How to I remove the parenting.  I've tried to set it to universe but no matter wha I try I cant undo it..

if you're on Poser5/up, try my ParentingPoses in my freestuff here.  there's an Unparent one that will remove the parenting for you.

or just try saving this as a pz2:

{
//Unparents the current selected prop. based on //'HandBall.pz2' by Les bentley. P5up.

actor $CURRENT
 {
 smartparent UNIVERSE
 
 }
figure
 {
 }
}

Why are you trying to parent/unparent a hand?  It's part of a figure.  I'm not quite sure what's going on here, I thought you parented a prop to the wrong hand.

Why are you trying to parent/unparent a hand?  It's part of a figure.  I'm not quite sure what's going on here, I thought you parented a prop to the wrong hand.

I parented one figures hand to another figures hand so the hands would move together (like to people walking in the park swinging their arms).  it seemed that it would make it easier to pose them.....

But i chose the wrong hand and what to get back to the begining or default parenting.

I'm not using a prop just two figures in the scene.  just trying to understand the whole parenting thing.

perhaps parenting figure body parts is not correct. if not how would i go about linking hand movement of one figure with another.  would using a hidden prop (say the ball) as a bridge be the way to go ???

I understand now and using a hidden prop that you can parent to both hands would seem to be the logical solution.  You can make one out of a Poser primitive, parent it to one hand, pose the second hand appropriately and parent it to the prop and everything should work the way you want.

Of course, I've never tried this so someone else with a little more knowledge may have a better solution for you.