That really does sound like Malware, or a nasty virus. I would boot up in safe mode and download Malware Bites and a few other things and then run them (while still in safe mode). That should hopefully clean out most of it, but when you boot back in regular mode, you'll need to run the cleaner again. Worse case scenario, most PCs have a restore partition (this has been standard for at least ten years) and you can just reinstall windows. You'll loose everything on the PC, but it looks like that might be the case anyway, if you think it's so bad it needs replacing.