Updating my os windows xp home edition [sp1]?

most of all programs that operate on windows now require service pack 2 or 3,to update your computer so it'll be secured for todays internet,you need to start using the windows update from microsoft,it's free to use if you have xp/vista windows on your system,i have the same dell 2400 you have here>to use windows update click start>all programs>on the top of the pop-up list click on windows update,agree to all the require software to dowload updates to your system,i have a 34 gb hard-drive on my dell 2400,and with all the updates and service packs use 11 gb of the 34.5 gb, u need to also turn on windows update so it'll update your computer automatic,you decide what you want to install,but install service pack 2 at least,then what ever is priority in the update list after it scanned your system. good luck