Re: partitioning a hard disk to install two os
Have you got 1 OS installed already or are you starting from scratch (reformatting first?) If this is the case then it should be easy, the setup process for XP (and most likely server 2003 though I've never checked) allows you to create different partitions on the same drive and then select what partition you want to install on.
So I'd recommend following the XP setup process through, but when you're making your partitions make 2, one for XP and one for server 2003. Follow through the XP install process and put it on one, then install server 2003 and when it comes to select what partition to install it on, select the other partition you created in the XP setup process (i.e. the blank one!) it should then install side by side with windows XP and create the relevant boot.ini entries you need.