Hi Johnny
I downloaded and installed SP2 from MS's website, it's a big file and at
that time MS did it by downloading bits each day over several days. When I
got the message it was all dowloaded and ready to instal first things I did
were a full system virus scan, a full system tidy up, a registry clean, then
left click My Computer > right click C Drive > Properties > Tools and did the
Drive C error check just in case, did the reboot to get that done, then I
went into each of the tools and apps I'd picked up and usually have set to
run on start up and set those all to not load so as to keep them out of SP2's
way (Basically that put the system back to pretty much a standard basic one
and freed up as much by way of RAM, etc., as possible for SP2 to do its thing
in). Then I restarted the machine three times to make sure XP had fully
absorbed all the changes I'd made and everything was rock solid, and then I
backed up my personal files and told XP to do a restore point, worth doing
that last thing I think even if only because it gets XP to charge around all
over the place and to verify it doesn't report finding any problems in doing
so. Then I installed SP2 and did exactly what it told me to do in the
install. That was about a year ago and so far I've had no problems from it at
all.
I very much suspect that most people who report problems installing SP2 get
them only because they insist on trying to put it into systems that are
already in terminal decay.
Point to note:
SP2 downloads onto your drive as 500 MB. When it installs that huge file
makes a "true SP2" of about 700MB, and that turns about 500MB of your
existing XP files into a 500MB archive and copies across the 700MB of "true
SP2" new XP files into their place. So, at the end of the install you have
maybe nearly an extra 2GB of XP related files. I raised this before elsewhere
and the recommendation is its probably best to not delete any of them because
(1) if you ever get a problem where you need to reload your original XP
anytime you'll need the SP2 download to finish that off anyway, (2) XP would
probably need the rest to do any uninstall and reinstall of itself, and (3)
no one knows if any future modifications to XP might assume all the various
files are still on your drive. Makes it a bit of a bind because it means
clean up utilities, etc., will of course be grinding through an extra couple
of gB for little reason every time they run, but I supose that's why we have
the larger dics drives these days.

Albert.