In my comment regarding changing the default PDF program, there is an option in the dialog following choosing the “install to” location where the user can uncheck a box, labeled Open PDF files with Perfect PDF.
At the end of the install, the program will try to open Internet Explorer 11 instead of your default browser. This was a common practice a few years ago (use Internet Explorer). These days, Internet Explorer is not installed on most computers, and Microsoft wants everyone to make the switch to Microsoft Edge. I don’t have either of those installed so I cannot tell you what the company is wanting the user to know. It could be that you have won a million dollars, but then again …