That is correct, Visio 2013 won't work on XP.
Nothing embarrassing about XP, most of our company machines are XP and have only recently moved to Office 2007!
I have to support a Visio app on XP, Vista, Win7 and now Win 8 and Visio 2003 (not Win

, 2007, 2010 and 2013 (not XP).