Great suggestions, but why are you using a Dell? Just kidding! :P
Because it was given to our non profit ministry, thanks be to God, to replace my old 650mhz white box (also a gift), on which i ran W/98se for about 6 years, then jumped right to Vista. XP came in because it was orginally set up that i would build my own, and found a legal retail copy of XP for 110, so i just installed it as a dual boot. I have also tried many Linux distros, and could tell why they are not viable for me.
I would not recommend Dell however. I prayerfully searched to help my downstairs neighbor find a low cost PC, and found one that flies, even though it he has it more loaded at startup than this one. I do not think you can build one much cheaper. http://www.computerlx.com/product_view.aspx?t=&product_ID=670 Upgrade the ram to 4gb, and select an OS. Praise the Lord.