Could not connect to Steam network

When I start Steam, there is first the "box" with "connecting steam account *name*" but after that this comes up:

Steam - Error

Could not connect to Steam network.
This could be due to a problem with your Internet connection, or with the Steam network. Please visit http://www.steampowered.com for more info.

Anyone here knows what to do, or have had this problem and knows how to fix it?

I've checked a few forums for solutions but they haven't worked. D:

Blumpfgh.