Ahhh, sorry, I thought the error was appearing after installation.
So, when you get to the point in the installation where you need to enter the share details, are you using the share name supplied when you created it? If you right click over the shared folder and select sharing it should display a network path. That should be what you enter into the box.
Looks like it's sorted. I was using the reference to the C drive but needed to use the server name. Thank you so much for your help. It's still running now but if I have any further problems I'll let you know