Check the
Oracle's Certification Matrices to see whether XP Home Edition is certified with Oracle XE. If not, you're out of luck; as you've already said, there *are* people who made it work, but those were exception to the rule.
XE might work on XP Home Edition, but noone can guarantee it will really happen. Perhaps it is a combination of someone's hardware, installed software, antivirus program, ... who can tell? If Oracle database you'd like to install on operating system which is not certified with it - well, good luck!
Oh, yes - I can't tell anything from my own experience as I installed XE on XP Professional Edition. Sorry for not being helpful.