User Account Control bugs you when you make changes to Windows settings. Microsoft turned down the volume in Windows 7, but they’ve also opened up a massive security hole that leaves PCs exposed to nastywares. A script can turn off UAC entirely, without prompting, by emulating a keyboard input. The fix is simple: Just make UAC modifications always require a prompt. In the meantime, you might wanna slide your settings up a notch, if you’re feeling paranoid, in the meantime.”]
Source: https://gizmodo.com/huge-security-flaw-in-windows-7-user-account-control-5142837