Why is preload taking up so much HD Room???

[Diablo6.0]

Can some please explain why the sw_preload(clean out of box) already has taken up 20+gigs basicly its factory settings? What can I do to create more hard drive space (i have already uninstalled uncessary progames)? Oh yeh i own a X300 btw...

I understand factory settings shouldnt take up that much hard space, but 20+ gigs is kinda insane.

[Marin85]

Are you sure that sw_preload´s size is over 20 GBs or just that C:\ has less free space? (sorry if I´m asking the obvious)