Download bypassing security, How?

[Toffeelatteplease]

So DD had managed to install a game on her computer which whilst plausibility innocent; does have some concerns about content (Rodblox). I'm wondering how she has done this as to install anything you are meant to need my password, she says nothing came up and I've just followed her steps and she appears to be right (not there was no warning it was downloading/installing but there was no password request). I'm wondering how/if I can prevent this
running internet explorer 11, and windows 8

[Tomzski]

Are you running any other security/family safety programs or are you using the family settings built into Windows 8?

[Toffeelatteplease]

just the windows family settings.