Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
The place where you enter numbers (which you see in a graphic) is called a 'Captcha' function.
It might be that it is governed by a Flash media function, that displays the image and compares with your entered keystrokes. If that is so, then if your Flash player has been corrupted, on your computer or in your web browser, then you would have the problem you have described.
If you are using Internet Explorer, it's simplest (perhaps) to just switch to using Mozilla Firefox instead:https://www.mozilla.org/en-US/firefox/new/
is where you could download the installer for Firefox.
If that isn't a (temporary) solution that would suit you, then I advise you to go to the Adobe.com download site, download and run the 'remove Flash Player' application, then restart your computer, then go back to the Adobe.com download site, and this time get a new copy of Flash Player, then install it.