Increaseing Volume space for Hyper V on Storage

I have windows 2008 SP2 as the main system. I also have installed an instance of 20GB storage drive on my storage which is as a drive on the host system where the hyper V file is located. I have installed windows 2008 SP2 on that hyper V instance for my file and print services. I am running out of space on the Hyper V instance. I have managed to increase the space on the Host system But when i run the hyper V on the windows 2008 on the Hyper V i am not able to see the increased space which i have extended on the host system after i start the Hyper V.

Kindly Assist.