Computer Very Slow? What is the best way to bring computer back as new?

All programs are dragging very slow (i.e. Internet, Word, Exel, etc.) My computer is approx. 2 1/2 years old. I am willing to erase everything on it, and start over. I do not mind backing up my files etc. I have deep scanned with new norton antivirus, ran up-to-date spyware programs, defraged hard drive, cleared temp internet files etc. Nothing has worked! I have an hp zx5000, intel pentium 4, 3.2 Ghz w/512MB and am running Windows XP Home w/Service Pack 2. I would appreciate if someone could give me some ideas as to what direction to take to solve this issue(in detail would be greatly appreciated). I do not want to replace my notebook, but I understand technology updates very often. With that being said, Is this computer still up to par with some of the mid-range notebooks today? Any help would be greatly appreciated. Thanks...

Computer Very Slow? What is the best way to bring computer back as new?computers

Without checking your performance while the PC is running, I can't determine exactly which resource is constraining your performance. Still, you have performed many of the steps I recommend to folks in similar situations. A few more toughts for your consideration:

1. Your antivirus and firewall software will significantly slow the performance of high-end games. It should be noticeable but not terrible for web MS Office apps. Consider using a router (%26lt;$100) to protect you from active Internet attacks so you can turn off the firewall software in your PC. Also, *carefully* consider turning off your antivirus software when using apps that do not bring new files into your PC. In other words turn AV on when accessing E-mail, but perhaps turn it off for Word, Excel, and routine web browsing.