I'm using a newish laptop with Windows 8 (eugh) installed, and just recently, web pages which I've used without trouble in the past are refusing to load. Facebook, eBay, and a couple of other sites are affected, but AW isn't, and nor is my webmail service, and most other stuff.

When I try to open eBay, for example, I get this error message:

Problem loading page

Server not found

Firefox can't find the server at www.ebay.co.uk.
When I click on a link to take me to one of the troubled pages the new tab appears immediately with the "problem loading page" message at the top, as if the computer hasn't even tried to load the page. When I refresh the page it grinds away for a while then reverts to the "problem loading page" message again.

When I try to open Facebook it partially loads the page but no content is displayed. The login boxes appear, and despite my having cleared cache and everything, including my passwords and so on, it remembers my login details. This confuses me.

It's happening on both Firefox and Internet Explorer (the only two browsers I have on this laptop).

Our other laptops seem fine, and load the pages without trouble. I'd really like to be able to get this one to work properly, though. I've cleared the history of both browsers, including deleting the cache, cookies and history.

Am I doing something obviously wrong, and can anyone suggest what I could do to resolve this?

Thank you for all suggestions.