What's a Service Pack?
Software, at its heart, is just text. It isn't all that different from the squiggles you're reading on this page. Either way, someone sits down at a computer and types one word after another. In the case of this book, your brain takes the words and synthesizes meaning. In the case of software, a computer takes software text and synthesizes instructions.
The point is this: both the book and the software code are subject to change. The text you're reading now is vastly different from the first (several) drafts of this chapter, and it's entirely possible that additional drafts will be written, published, and eventually sold in later editions of this book. The same goes for the operating system this book covers. It is a constantly evolving entity.
Generally, there are three ways in which an operating system can evolve. New code is distributed through patches, hotfixes, or entire Service Packs.
Patches are usually released to address specific problems or bugs that have been identified in programs. Patches are pieces of code inserted (i.e., patched) into an existing executable file. Patches are typically available as downloads over the Internet and are released for almost every imaginable program.
A hotfix is code that is not inserted into existing programs but rather is distributed as an executable file. It also usually addresses a specific issue. The difference is that a hotfix can often add functionality. When XP installs a hotfix, backup files are usually created so you can rollback the hotfix if you want.
Service Packs are much more comprehensive updates to software packages, whether they are individual programs or, in our case, the XP operating system. A service pack marks a significant upgrade to the program and can address compatibility issues, security issues, stability issues, or all of the above. It usually includes a roll-up of all previously released hotfixes and patches and can even introduce new features.
This chapter identifies the new features of Windows XP's Service Pack 2 and also walks you through the installation process. Along the way, I'll highlight the changes you should expect from this significant upgrade.