Wifi adaptor shows no connections are available

I am having a major issue....

I have a samsung laptop with Windows 8.1 (64 bit) and Inten Centrino Advanced-N 6235 network adaptor.

Yesterday morning I was using the laptop as normal at home. I then took it to work and was not able to connect to the internet. When I looked at the network icon in the bottom right it had a little star and said "not connected - connections are available" but when I click on it, the pop up says there are no connections available.

Yesterday evening I took it home and when I switched it on, it connected to the internet straight away, I hoped that it might have fixed itself, but today I have tried again at work and it still says the same. I have gone round the corner to a friend's office who I know have wifi and it still says exactly the same.

I have tried a number of things:

Going into the adaptor setting and checking that it is enabled. Disabling, re-enabling, restarting and still nothing.
Connecting with an ethernet cable I have looked for automatic updates for the driver, this has not improved it
I have since unistalled the driver and reinstalled from the Intel website, still nothing. This driver included the proset manual diagnostics tool. When I run this, it passes the scan test (confirming that there are 7 networks available to connect to) but fails the association test as I have removed all of my previous networks.

I am now completely at a loss and don't know how to fix it, any suggestions?

One extra piece of information worth knowing is that when I got to work yesterday the wifi network I had been connecting to had been re-set and so my logon details had changed, I know this because my phone did not connect either, but I have since resolved this on my phone. When I first went into the adaptor settings the status did say it was trying to connect to this network. Since this wasn't working I instructed the computer to forget this network and have never seen it since!