SmartScreen, in Windows 7, was an anti-phishing technology built into Internet Explorer. It’s still working for you in Windows 8.1. If you try to visit a Web site that Microsoft knows is suspicious, it blocks your path with a huge warning banner.
In that situation, close the page, click “Go to my home page instead,” or go to another site. (If you’re just researching phishing sites, and you know full well what trouble you’re getting yourself into, and you really want to proceed, then click “More information” and then “Disregard and continue”; you’ll go through to the phony site.)
If Internet Explorer isn’t quite sure about a certain site’s phishiness, but it has a funny feeling in its bones, a yellow button appears next to the address bar saying “Suspicious Website.” Unless you absolutely know the site is legitimate, it’s a good idea to head somewhere else.
In Windows 8.1, SmartScreen has grown a lot more powerful. Now SmartScreen also warns you when you try to open a downloaded program that might be fishy, even if you downloaded it in a browser other than Internet Explorer. One day, when you least expect it, you’ll get a pop-up warning.
SmartScreen works by comparing the file’s original Web site address against a massive list of Web sites and file downloads that have been reported to Microsoft as unsafe. If it blocks the program you’re trying to open, just click “More info” and then (if you’re sure it’s OK) “Run anyway.”