Hi,
I use custom quick support links for most of my customers. Whenever I instruct an end user to go to my link and run the app most of them just sits there staring at the background image with the spinning thingy saying "Loading Teamviewer".
I say - Run the app. And they reply - OK it's loading.
I then wait a minute or two before I ask - How's the progress to which they reply - It's still loading.
Then I have to instruct them to run the file in the bottom left corner (Safari is even worse).
This usually takes more time than to actually fix the problem they were calling for.
All due to a stupid background (and of course stupid end users). And this is in at least 70% of the cases I handle.
My suggestion is that you look at what for example Adobe has done with Adobe Reader. The background instructs the user to click the downloaded file. Or at least have a none-misleading background image.