you should still be able to do it during an XP install if you press F5 when you see the press F6 message.  Pick "standard PC"

 

Seriously though, you shouldn't have to do it.  Creative just has terrible software, especially for their older products.  Do you need this specific software from them?  Usually the driver package is enough to get all functionality of the card -- the extra programs they offer are primarily useless fluff (in my humble opinion).