Recently, a co-worker was trying to set up an account on a website, which is part of her job. When she clicked on a link on the page, she received a pop-up message warning that the copy of Windows on her computer had been deactivated. To proceed, the warning said, she needed to call an 800 number and talk to Microsoft to get things going again.
The pop-up covered the entire screen. In fact, the page had put itself into full-screen mode in the browser, so it was hard to figure out how to close it or continue.
After a few tries, the pop-up finally was closed. She was then able to quit the browser and run a malware scan. The scan found nothing.
This was just a rogue pop-up, sitting on top of her browser window. The scammers were hoping it would scare her enough to make a phone call. The first step on the phone would have probably involved getting her credit card number or allowing the scammers to remotely control her PC.
To be clear, this pop-up launched when she clicked a link on a legitimate page she was accessing.
Microsoft will never interrupt your day with a pop-up window asking you to call an 800 number.
According to the company, "Scammers might also initiate contact by displaying fake error messages on websites you visit, displaying support numbers and enticing you to call. They can also put your browser on full screen and display pop-up messages that won't go away, essentially locking your browser. These fake error messages aim to trick you into calling an indicated technical support hotline."
It adds: "Microsoft error and warning messages never include phone numbers."
If you're at work and get an unfamiliar error message or a page telling you to call Microsoft, don't click on any links or call any phone numbers listed on the page.
If your office has an IT staff, call them before you do anything else.
If you're at home and your computer gets stuck on a pop-up or frozen browser window, don't panic. Chances are force-quitting your browser will do the trick. Windows users can press Control-Alt-Delete and launch the Task Manager. Find the browser and click the button to End Task.
The next step is to reboot the computer. After a restart, things should be better.
If you see the same message again, there's a good chance you've picked up some malware. You should run an advanced scan on Windows Security to get rid of the malware.
MalwareBytes is also a popular tool for removing malware on Windows computers. You should have a copy on hand to scan for problems when you are suspicious.