Ok say you enter two breed classes.. Ie Puppy and open... if you win the puppy class can you withdraw from open to remain unbeaten? (basically so you can go on to best puppy in show.

No - you can't withdraw from breed classes to remain unbeaten.  Not much point really, as you'd be beaten in the challenge anyway if the judge preferred another dog.  But you can go into best puppy in show if you haven't been beaten by another puppy.

Sadly not!  But provided the open winner wasn't a puppy dog then you would still be able to compete for BP.

Just to say, it isn't really the "done" thing to enter a puppy in Open -even if there only are two breed classes.  Always best to stick to as low classes as possible for pups, eg. puppy, junior, and for breeds with few classes perhaps PG at a pinch (I know in my breed sometimes the lowest class IS PG!We're lucky to have a puppy class at open shows) but Open is generally for the fully mature dogs and won't really do a pup many favours.

Thanks every one. As for what is and isnt the "done" thing.... still learning im afraid:rolleyes:....sure im not the first and wont be the last, but will no for next time. thanks for the warning

If you want more practice at showing/handling then you'd be better off
entering in the Any Variety classes.
These are commonly after breed classes.
You can go into AV Working (can't remember do you have a Boxer? If not you'd need to go into the right group classification) puppy, AV Minor Puppy or AV puppy (the last two are age restricted so check to make sure that your pup is entered in the right age class).

If you win in your breed class you may withdraw from the AV's to remain unbeaten.