Windows' own built in tool allows you to overwrite files with the same name, as the disc isn't closed. It's only when the disc is closed that you cannot edit it.
On a DVD±R or CD-R, the space cannot be reclaimed, as it is permanently burned in and can't be filled. You can only reclaim space on a DVD±RW or CD-RW.
NZ PC World recently review an Alienware laptop which has gaming specs, including the graphics card, which is an ATi Mobility Raedon 3870, and even has an option for a quad-core Core 2 Extreme. :biggrin: