They say condemn the sin and not the sinner and then I haven't had much disgrunts about Windows if I think back of the days when I was purely a Windows dudette. I do prefer OS X over Windows but not so much so that I'd let bashing Win XP dominate my days here on this earth. But why did I do this one?
I've gone back to dual booting as you may well know. I've no idea what went wrong but PC_EFI alone wouldn't do the dual boot trick for which I turned to chain0.
Setting it couldn't be easier, and in XP too:
1) Download and unzip chain0 to C:\ - or whatever drive your XP installation currently resides.
2) Go to My Computer > Properties > Advanced tab > Settings. And from the System startup section, click on Edit: