(newbie) new version install (winXP) ?

[Stef Mientki]

I've been started with Python on winXP,
by installing the "Enthought" edition (about half a year old).
This works like a charm.
As a regular windows user,
I'm not used to install partial packages.
Now I find interesting application,
that require higher versions of certain packages.

Can I install only the higher version of a certain package ?
Is that done by simply copying them ?
Should I make a backup (of what) ?

thanks,
Stef Mientki