Although you can create a slipstream installer using nothing more than the Windows command prompt, a free helper application called nLite makes the process easier.
Follow these steps:
Download and install nLite:
Download nLite from http://www.nliteos.com/download.html.
Click Save when asked what you want to do with the file, and select your Windows desktop as the destination.
When the download is complete, double-click the nLite file on your desktop
(which may have a name like
nLite-22.214.171.124.installer.exe). If a Security Warning dialog box appears,
Follow the prompts to install nLite. (You can accept the default settings in the installer.) When the installation is done, make sure the Launch nLite checkbox is selected and click Finish. ...