Less experienced users can't do that -- they have to read every single word on the screen and make a decision about it. They mitigate this by memorizing specific actions. i.e., "to send an email, first I click in this area, then I click on the blue thing, then I click in that area..." (which is why constantly changing UI is such a problem for them, btw).
So what do they do with installers like this one? They just click "Next" with all the defaults on. The text on a screen like this is no different to them than the text of the EULA that none of us read.
Amongst my non-computer literate friends, many of them adopt the "click next quickly until the install starts or it stops working" tactic.