There is no express or custom install for ImgBurn If you read the title / heading of the page you're seeing that on, I'm sure you'll actually see it says about installing a 3rd party program (these 'advert' pages are inserted by the OpenCandy plugin)
As in, it'll say:
'Install [such and such]'
' Recommended by ImgBurn'
You're free to opt out of anything you don't want, it has no effect on the installation of ImgBurn itself.