Ok, before you all call me crazy.
My sister needs a new computer. I told her I'll build it if she lets me crunch on it.
SHE AGREED!! Now, I only have a $400.00 budget.
This is what I have lying around.
Old case with fans,
HD,
os (Win vista),
monitor,
and I have 2 hd 5870's to put into the box.

The computer will be used by my niece for homework and internet. I'll need a PSU, MB, a processor, (hoping to go with an Amd 6 core if it fits the budget) and memory.

All help is appreciated.