From what you posted, it appears your system doesn't have the horsepower to
run XP, home or pro in much more than a slow pace. I can't answer your
question, I don't know why you made the change in the first place if pro was
running fine. If it was, than either there is something wrong with the
specs you posted or there is something amiss in how home was installed. If
your original XP Pro was a recovery disk, you might try running that as that
will set your system back to its factory fresh condition. Given things
you've mentioned, I can only suggest, if that doesn't return your system to
a satisfactory state that you call your computer's tech support or take it
to a shop or the place where you purchased it for help as I don't have
enough information to help you any further. That is, I would need to be
physically at your computer to see if I could determine what is going on.