Am I all set for a reformat?

Hey everyone. I plan on doing a reformat, but before I get started with that, I am going to put everything I want on to an external hard drive for later retrieval.
(The reason I am doing this is because my computer is getting really slow with loading files, the registry is a mess even though I use CCleaner, Defrag, and virus softwares like norton, malwarebytes.. etc.. and my computer is 7 years old now…)
After I got all my songs, pictures, movies, and whatever else on my external hard drive, I am going to reformat. My computer came with the following CD’s

-Microsoft Works Suite 2003 (Disc 1-5)
-APPLICATION For Reinstalling Dell Tools System Software
-APPLICATION For Installing/Reinstalling Roxio Easy CD Creator 5.2 Basic
-Drivers And Utilities Dell Dimension Resource CD (Contains drives, diagnostics and utilities and computer documentation.)
-OPERATING SYSTEM Reinstallation CD for XP Home Edition SP 1.
-Sound Blaster Live!
-Norton Antivirus
Ahh thanks for reminding me to backup favorites!

Anti-virus software?

I don’t have an Anti-virus software installed in my computer. That’s because I’ve upgraded to Common Sense 2009. Why buy pricey anti-virus softwares when you can use your brain! That’s right, If you actually put your mind into removing any virus from your computer you’ll realize it wasn’t that hard. All you’d need to successfully run Common Sense in your computer are:

1. Google
2. A brain
3. Internet access.

Why settle for crappy software that tend to scare the shit out of you and annoy you when you can easily notice when you’re computer is slowing up and acting strangely run diagnostics on it and presto. You’ve successfully used Common Sense 2009.

Which anti-virus software do you guys use?