wmp 8 or wmp 10 upgrade

Dell ,win xp home, have sp1 (not yet sp2)
Hi- I got my pc 2 years ago. With it, came installed several programs.
including wmp 8 ( think its '8')-Ive been reading about people who have
'10'. I have been reluctant to upgrade different programs I have because
they seem to come with faults; like sp2, & several other programs. So I
tend to wait till I guess they get things fixed-Im kind of a newbie & afraid
to mess things up if I just upgrade everytime a program has a better
version. Well, I'd like your input if you think that I should upgrade and
what problems need to be addressed before or after installation.
BTW, Also have Roxio version 5,and real one version 2 (i think)
is upgrade *free* ??? I 'll assume its a matter of preference but I like
opinions- thanks for your time