Right now I have a AMD A64 4200+ AM2 Dual Core processor from my old comp I was gonna give her, but if you guys and girls could list some cheep ways of upgrading then it be much appreciative. I would like to note I don't want to build a machine that would run crysis at 60 fps but just an average fast computer that would help my sister do what she needs to do

Here are her PC Specs
Mainboard: Asus A7N8X-LA
Chipset: nVidia nForce 2 IGP
Processor: AMD Athlon XP @ 2083 MHz
Physical Memory : 1536 MB
Video Card: Nvidia Corp GeForce4 MX Integrated GPU
OS: Windows XP