Gecko question

Wow there sure are a lot of options with this CNC stuff :) I keep
flip-flopping between a camtronics driver and a Gecko driver. I am
beggining to lean towards the Gecko just for the "ease" factor. I
have read that in addition to the power supply for the steppers you
need 5 volts to also run to the box from your pc. I have also read
about people tapping into a extra HD power cable in their Pc for this
5v, I am planning on using a old laptop I have laying around, where
would I get the 5v needed from this? Again thanks for the patience
and help.

Matt