Windows Defender Security Center scam: How to protect your computer from fake pop-ups

In an email we received from Janet D., she shared her recent unsettling experience. Here’s what she described:

"I received a pop-up that froze my computer and read, ‘Access to this system is blocked for security reasons’ from Windows Defender Security Center. It came with an audio message and siren."

Janet did what many might do in such a panic-inducing situation: She called the number displayed on her screen. She was instructed to press Ctrl + Shift + Esc, unfreezing her computer, but the instructions didn’t stop there.