I Rented A Popup Camper Why Does My Computer Suddenly Have Popups? Did I Download It Or Not?

Why does my computer suddenly have popups? Did I download it or not? - i rented a popup camper

My team is normal. There were no pop-ups or anything. Then one day something appeared and said something like: "The team needs to download this program majiggy thingy. I decided to cancel, but accidentally clicked Yes, then a page is loaded. I finished quickly, before pagewas has finished loading. Then as a few days later there was a pop-up does not believe in a hire car. I closed and came after about 5 minutes, another pop-up. I'm not very good with computers and I can not find its way into the future be downloaded (I do not trust Blocker from the Internet anyway. HAV could be a virus, somewhere in there). Well, sometimes the desktop icons disappear, can not access the Start menu do not work right. So, forTHIS I press the reset button on the computer, and I do not think that is good for them. I have already investigated and found nothing. What should I do now? Please help!