You have some very good replies from some of the "old-timers" here and they
all have suggested that you install Service Pack 2. They know what they're
talking about. But they haven't given you the option of not installing SP2.
There are specific steps you need to take to prepare your system for the
installation of Service Pack 2. If you go to the Windows Update website,
you can check out these procedures for yourself. Briefly, they include
running a defrag, ensuring your system is free of viruses and malware,
updating drivers and so on.
I personally have not installed SP2 and I don't intend to do so until
Microsoft makes it a prerequisite for downloading future updates and service
packs. There is no reason to install SP2 if your machine is protected by a
good firewall, anti-virus application and good spyware and adware scanners.
You can continue to install the critical updates released regularly while
declining to install Service Pack 2.
Check out some of the articles written in such publications as PC World, PC
Magazine and Computer Shopper Magazine. Not everyone has good things to say
about Service Pack 2. If you do decide to install it, I would most strongly
suggest you backup all your critical data and inquire as to the
compatibility of your applications with Service Pack 2.