After some digging around the interweb a while back I discovered that there is two separate methods to running an existing Windows partition in VMware.
I take credit for none of these websites-
This I have tested and does work, however as McMonarch mentioned there is issues with using the same Windows partition. There is a method around this which I will mention further down.
Another example of the VMware server method.
This method involves a little bit of trickery with the program 'parted'. The instructions are clear. I couldn't get this method to work mainly because of my slightly dodgy MBR.
To get around the activation problems with running Windows on effectively two machines I discovered this tutorial that works, I have tested and confirmed this myself.
This may be technically illegal in most countries so I don't endorse it, but I am willing to make the information available to the community.
Hopefully that helps the previous posters.
EDIT: Thanks gumbi18 for collating this information.