What is your operating system, version & edition?
What is your web browser?
User Account Control box appears only if it is enabled in your machine.
Do you see the Agreement box?
I hope you are on Windows and the following link has more info: http://helpx.adobe.com/content/help/en/flash-player/kb/installation-problems-flash-player- windows.html#main-pars_heading_6
Please provide us with the details Pat asked.