Hate to disagree with Colin but it's more likely your computer has been infected by malware than it's suffering RFI.
I'm wary of advice offered on the web because quite often it ends up asking you to pay for something when a little research would let you fix it for free. However, have a look at this website, which seems benign. If the site directs you to a commercial product like Malwarebytes, look carefully to see if they have a free download version tucked away: you may not need to cough up for the full product.
One of the reasons I prefer Linux is that it is almost immune from many security problems. Switching operating systems to cure your problem is likely to be overkill, but if you like Windows, you really have to be on the ball when it comes to security.
Please report back. I get asked to fix various family computer infections and am interested in how others get on, and how vicious the infection is. Yesterday I took less than 10 minutes to find and destroy an invader, but that was unusually easy. A couple of years ago it took me 3 working days to clean my daughters machine when she came back from university. It took me 2 days to remove just one nasty from my ex-wife's laptop. That was "fun" because she'd caught something capable of disrupting attempts to download repair software! I had to download the software on to a different computer, copy it to USB stick, and install it on the sick machine manually.
You're unlikely to need all of these but, in addition to the usual AVM, I've used these tools: ccleaner, HitmanPro, Malwarebytes, rkill, tdskiller, and the EmisoftEmergencykit.
Once cleaned up, I can recommend AdBlock+. Apart from that, be aware that when downloading a wanted thing, it may come packaged with muck. For this reason I try to get device drivers and software from the originator, and avoid the general purpose download sites pushed by the search engine.
Good luck,
Dave