... unless the site was saved in my bookmarks.
I have Firefox and have done a virus check with Antivir, which showed nothing.

Can anyone help me.

Thanks

Can you see sites that are entered manually into the address bar?

It might just be that your homepage is down or the address is malformed.

no i cant. only when i use my favourites

Exactly what happens when you type in an address? Does it come up with the 404 error?

well I have just tried a website and it worked. I can't however, get on Facebook or google search from my homepage

Which ISP are you with? BT? I had dns problems yesterday (in Darnall) turn off your router for a bit, it might be the same problem, mine seemed to pick up a new dns server.