How do you block any web pages from the computer?

2 days ago commercials web pages(music,insurance,etc.)started appearing at my computer screen,I tried to see if something was downloaded in my computer to allow these pages,but didn't find anything.so what do i need to do stop these annoying pages?

e Friend of mine ask if he could barrow my computer to check his email and what he did is get into a porn web page i need help because my kids uses the same computer so is there any ...show more

Can i block some web pages which they come up automaticaly. In this condition very difficult to use my home computer. So please give me some advice.

I need help in deciding which format to save Web pages in. I'm including the info I got from my Explorer Help file on this, which gives me 4 options, which I've copied & numbered below. I understand option 4, text only, but sometimes I want to keep...

I have the option to block specific pages of my website from crawlers/spiders. Can doing this to a few pages (not the main of course) hurt my position in a search. I thought it might be a good idea to block the Contact Us page and a few others like Login...

In the past few months certain web pages show up on my home computer as mobile pages designed for a phone or other small device. Instead of saying www.xyz.com it will say www.mobile.xyz.com or www.xyz.com/mobile. It makes the page completely unusable...