I've seen several reports of installation failures that are caused by problem during the download of material libraries. My first suggestion would be to verify that you have an active internet connection and that you have disable any anti-virus software, which may block content from being downloaded. If neither of these suggestions help, please post your install log file, which will be located in your Windows temp folder.
Tony Michniewicz
Autodesk Revit QA
Tony Michniewicz
Revit Software QA Analyst