Hi David,
Sorry to see you're having problems. Can you check to see if the AtikAir service is running on your PC. To do this:
1) Open Task Manger
2) Click the 'Services' tab
3) Find 'AtikAirService' in the list.
4) Under 'Status' it should say 'Running', if not, right click on the service and click 'Start'.
That should get the 'AtikAir' application (in the toolbar) working again and from there, you should be able to set up your raspberry pi as usual. If not, I would suggest re-installing it from the Core Installer.
Let me know how you get on.
Chris.