|Thanks for you help guys.|
I tried Malwarebytes in safe mode but it didn't find anything. I then downloaded Superantispyware and it found a number of things. I cleared these off and hey presto! I could use the internet again.
No idea why, but neither Malwarebytes or Spybot (both fully updated) could seem to find anything.
Anyway thanks for the help...running a scan was all I needed to do as you said (although with different spyware)