Invest in something like PowerQuest Drive Image, which I believe has been
bought out by Norton and is now part of Norton Ghost now, and make a backup
of your C: drive. If it screws up, revert back to your SP1 image.
Unless you are one of the very few that had terrible issues, it is a pretty
painless upgrade to SP2. I find my system more stable now than before. You
may run into stability issues with 5.1 and higher if you DON'T upgrade to
SP2.
I think it is fine for most people. Unfortunately there are some bits
of hardware that SP2 doesn't like and I am unlucky enough to have two
of them. I tried SP2 for a while and was able to uninstall it just
fine when I found it wasn't for me.
If you do make sure you turn off any anti-virus and/or 3rd party firewalls
before attempting. Someone didn't do this on a friends computer and the
install wasn't completely successfull but didn't give error messages. I had
no problem getting it installed on his machine or mine.
M$ has a list of known problems. Just look to see if you have anything thats
on it.
I'm quite happy with Service Pack 2 myself. I'm running it on both of my
computers nicely. However, I heard a game called Freedom Force does not run
under Service Pack 2. Has that issue been resolved via a patch or otherwise
now? I believe Microsoft has posted a list of software that may not run or
run properly on Service Pack 2 somewhere on their website.