I downloaded and installed the demo version, but it ask me for a Username and Password. What are the Username and Password?
You don't need any Username or Password to use the demo version of the application. I suggest you to uninstall the utility using Add or Remove Programs feature and to visit the official web page for a new copy. Fill up the provided fields, press the Send button, download and save the file to your computer and install it following the self-explained instructions. When you will open the program, be sure to check Demo version (21 days) instead of Retail version option.