Thanks guys, I tried Malwarebytes, Super anti-spyware, spybot search & destroy and AVG
From what I can make out, Cryptor is "clever" enough to block all of those from running unless you rename all the .exe files which I just couldn't work out how to do.
Spyware doctor correctly identified it all but I had to pay £30.00 to register it to get it to remove it but it now seems to have done the job.
Hopefully that will be the end of it.