Thanks Daveny5 for your reply. I have now managed to get it working.
The Cronus.dll file was not being scanned into the correct category in the Plug In Manager. Under "DirectX Audio Effects (DX)" I added a scan path to the cronus.dll file location so that this is scanned into this category. Also any audio file that you want to create a VVocal on has to be "Bounced to Clips" first.
Therfore if you highlight the audio clip, right click and select Bounce to Clips, then right click again and select Create VVocal Clip. This will then open the VVocal editor.
Thanks
System Info:
Processor = Intel i3 core 3.1Ghz
Op system = Windows 7 64bit
Ram = 16GB
DAW = Sonar X2 Producer (X2a Build 351)
Focusrite Scarlett 2i4 audio interface into Technics amp
MAudio Oxygen 49 Keyboard controller