Sometimes you can not install the Agile Platform Community Edition in your computer because of conflicts with a previous installation of IIS or with third-party software that runs on top of it.
In those cases, if you go to http://localhost/ServiceCenter/dobootstrap.aspx you will get a detailed error message from Microsoft IIS and you can try to google the message or follow the microsoft's kb articles to figure out how to fix the problem. Once the issue is solved if you try to access that page again you'll get a "bootstrap ok" message which means that you can retry the installation and it should work correctly.
Of course that if you have problems installing the Agile Platform Community Edition you can always click the Help Me! button and we'll help you to install the platform in your computer. This will also make us have more information on these issues and we can improve the installer for other people.