How to stop board trying to connect as com when plugged into a PC USB

I've programmed my leonardo board as a HID device (using a windows7 PC). When I plug it into my gaming machine (winXP PC) it gets recognised as HID device but also as an unknown device. I gather that is the com connection that the bootloader is trying to make ?

I want to be able to plug the board into any PC and for it to be recognised as a HID and not throw up a unknown device warning.

Do I need to disable or get rid of the bootloader? How to do that?

cheers,

Get rid of Win /XP.

Paul