Cleaning up Windows XP Desktop

I know this is mainly a notebook forum, but I love the amount of help I have gotten here. I have a question.

My family owns a Dell Dimension 4700. 5 people currently use it. I used to, but now I have my Inspiron 1420 and it isn't necessary anymore. The computer is 2-3 years old, and it is running very slow. It has 512MB of RAM (I see the problem there. 5 people+512MB RAM=SLOW.). I am thinking I can revitalize the computer to an almost-new state. I figure I can add in 2GB of DDR2 RAM and get it running smoothly again. But, I want to get rid of EVERYTHING on the computer, so that is basically like opening it up for the first time. Can someone walk me through all of this? (i.e. cheapest place to get RAM, how to clear out everything, etc.)

EDITED: If I do clear out my computer (running XP SP2), is there a way for me to get XP back onto it by using the XP disc that came with the computer a while ago?

Help would be very much appreciated. Thank you!

 

I have been reading around since I posted, and would this really be as easy as installing the new RAM, and then putting my XP clean install disc into the computer? Would that make the computer appear and perform like new?

 

well its a dell so you said it came with a recovery disk? just put the disk in and reinstall windows it will put the pc back to the day you bought it original dell software and all. what kind of processor is in that thing?

 

It's a 3.0 GHz Pentium 4.

 

And with the extra RAM should run better than ever! Once you do it make sure to maintain it, one of the best things you can do is defrag the hard drive regularly, scan for spyware and use an anti virus that does not hog resources. You should be in great shape. That Ram is going to be night and day diff!

 

yea that will run good with vista when you add the 2 gigs