1800 819 648 is a internet scam. Call the number on skype, (toll free) don't give them your real number, they will claim to be certified Microsoft technicians, they are not. They are intentionally trying to scam you of money.

I keep getting a message saying to ring this number to cancel pop-ups on my computer. It has been happening for several weeks now.

Yes the same happened to me yesterday. A grey box came over the top of everything whilst I was on gumtree. I couldn't close it. It kept changing things on my computer.

Just install Malwarebytes for free and run a full scan and it'll take care of it. Also it's fun to call these people and go along with it to waste their time. Good luck

BEWARE!!!! THIS IS A SCAM..

I also keep getting messages on my computer to cancel pop-up adds. Only started happening when I started using my mobile hot spot (tethering through my mobile). Doesn't happen on my home network. They don't call me, but whenever I'm online I get a pop-up navigation screen message asking me to call this number to disable pop-ups. Checked my settings in Chrome (searched 'how to disable pop-up adds in chrome'). Settings were already disabled so I should not be getting this message.

When you try to to close the navigation message box they send you, you are re-directed to another website (https://err-code-888d-netcheck.com) either requesting a live chat to "resolve the issue" or an online video of some girl directing you to select YES or NO on the screen for further assistance. The website looks very profession and legitimate but I suspect once you proceed they can get remote access to your computer. They also try to fool you by identifying the network you are with. Reported it to my internet provider who will be investigating further. Also going to report it to Scamwatch.

Hope this helps.

Me too and the same amount of weeks, it's annoying, what do we do to stop?