hadoop hardware suggestion

[PORTO aLET]

Hi,
I am trying to setup a hadoop cluster to process our apache log (about 500MB
a day).
I am just not sure what kind of pc configuration I should use?
We have a few windows xp machines (about 100+, too many to process 'just'
500MB ?) that I am thinking of using sparingly (during the night) to process
the logs.
So I am thinking of installing Linux in VirtualBox in them to run hadoop?
Please share your knowledge and wisdom,
Regards.