Place it at the cut where a dialog box fills the screen, then follow it with a classic error sound if the user clicks no, or a ding sound effect if they approve and the install continues.
Об этом звуке
The Windows 8 UAC clip is a sub-second system alert tone, the short chime that plays when the operating system asks for administrator permission. Hearing it brings an instant mix of familiarity and mild dread, like a program is about to change something important and you have to decide right now whether to allow it.