Default browser on web tuneup

Hello, 
My default browser is set to Chrome, but the program doesnt recognize that.
I've attached a photo to this email of what the program looks like. Web TuneUp isn't installed on Internet Explorer and it won't let me do anything from inside the program.
User-added image

Dean,

We understand your concern, please make sure that your default web browser is "Google Chrome". Then uninstall AVG Web tuneup extensions from Internet Explorer and download it in chrome. Check if the issue persists, we will assist you further.

How do I change my default browser in Web TuneUp from the desktop program? I use Chrome, and it has my default browser set to Internet Explorer. Not sure how to change it. It says that the web tune up isn't installed on my default browser and when I click on "open browser" nothing happens.
I tried uninstalling it and that doesn't work either, the window just closes.
How can I fix this?

Hi Dean,
We apologize for the inconvenience and In this case we suggest you to check with the google chrome and make sure once chrome is the default browser or not. After these process please follow the below steps to enable the AVG Web TuneUP extension.
Open Google chrome->Go to settings->Go to extensions->Then enable the AVG Web TuneUP option.
If you need any further assistance, please feel free to contact us. We are always here to help you with your issue.
Thank you.

Dean,

We understand your concern, please make sure that your default web browser is "Google Chrome". Then uninstall AVG Web tuneup extensions from Internet Explorer and download it in chrome. Check if the issue persists, we will assist you further.