Dear therules,
1. If Ajax Uploader detects SilverLight is installed on your PC, It will use the SilverLight solution.
2. If Ajax Uploader detects Flash is installed on your PC, It will use the Flash solution.
3. If Ajax Uploader detects Iframe is supported on your Browser, It will use the Iframe solution.
4. Ajax Uploader will render as default ASP.NET upload control.
Thank you for asking