When I try to open a webpage, I get the message 'Internet Explorer cannot display the web page'

First try opening a different page, it may be a problem with the particular website you're trying to look at – the site may be temporarily unavailable or experiencing problems. 

If you get the same message on other pages, then click on Diagnose Connection Problem. This will launch Windows' network diagnostic tool, which will scan for any network problems.

Also check your router to see if it's connected to the internet. If not, contact your internet provider as your internet connection may be down.