"Steam is having trouble connecting to the steam servers."

Since the Big Picture update, I can't even login to Steam and it brings up this message. Steam did work perfectly on my other laptop though, so it must be because of the installation.

Here's what I did:

• Deleted clientregistry.blob, deleted everything except Steam.exe and SteamApps.

• Changed autorisations in the Security panel of the Steam folder to Total Control for all Users.

• Disabled my Fire-wall, Anti-virus, Windows Defender and Windows Update.

• Tried launching with the suffixes "-tcp" and "-clearbeta" in the shortcut path.

I looked for the error in the Steam forums/support section, still no idea what I have to do. Halp? ;_;