Howtogeek shows you how to customize your Windows installation disc with WinReducer
First, download WinReducer 8. This software is technically in beta at the moment because of how new Windows 8 is, but it worked fine for us. That said, WinReducer includes a warning that it shouldn’t yet be used for production purposes. It’s okay to experiment with it on your own, but don’t use it to customize an entire organization’s mission-critical Windows 8 installer discs just yet.Customize Your Windows 8 Installation Disc and Slipstream Updates With WinReducer
Launch WinReducer after extracting it and you’ll immediately see an error message. The message tells you you’ll have to manually download certain tools that WinReducer requires — click OK to continue.