UAC doesn't prevent users from download files and software from the Internet, but can prevent users from running software that require elevated privelege (ie. admin rights). Be aware that some software can be installed on Standard / Guest user account without Admin rights or UAC intervention, for example, Firefox. Difference between
Installing in Program Files vs. Appdata.
You can Enabled/Disable File Downloads for
Internet Explorer only - Find out How to
Enable, Disable File Download Option in Internet Explorer
Free Home edition - (
RollBack Rx Home)
RollBack Home Edition is a FREE instant time machine for your windows workstation. It is a comprehensive Windows System Restore solution that empowers users and IT administrators to easily restore their PC’s to any previous state within seconds.
Free available - (
Reboot Restore Rx Pro)
Reboot Restore Rx Pro prevents any and all changes made on your drive(s) making those PCs bulletproof and unbreakable. It is designed for public access computing environments such as schools, computer labs, kiosks, hotels, Internet cafes, and libraries.
Free available - (
ToolWiz Time Freeze)
Toolwiz Time Freeze is an easy and effective Instant system restore software to keep your system safe and protect your computer from unwanted changes.
Turnning on the Time Freeze mode, the whole system is running in the "sandbox". Only the changes to the files in the exclusion list will be saved.
@Umbra can advise.