Steam Error - Could Not Connect To Steam Network

For the last few days whenever i try to open steam i get an error saying:

Could not connect to Steam network, this could be due to a problem with your internet connection or with the Steam network.

It was working perfectly well until the other day.
I haven't done anything different which would interfere with Steam,
only thing i can think of is i installed some updates from Windows Update.

I read somewhere online that it could be down to a .NET Framework but im unsure if its Framework 2.0, Framework 3.0, or any of the the ones.

I noticed on the Steam site that various programs could interfere with Steam, including Nod32, K-Lite Codec Pack & Daemon Tools which i normally use.
But i done a fresh install of Windows XP Pro SP3 & have only installed Daemon Tools.

Ive had a look through various forums & the Steam Knowledge Base but i can't seem to get into my account :/

If only i could even get it to start in Offline Mode, that way i can still be able to play the odd game in Offline Mode.

Anyone any ideas ??

Cheers