This procedure will only work if empty space exists on a Disk Volume that is not included within a disk partition.
Open a command prompt
Type "diskpart.exe" into the run menu and click OK and then you will see the command list volume:
Select volume number that corresponds to the volume that you want to extend.
example: type select Volume 1
Extend the volume with the extend command.
type: Extend
This will complete successfully if unpartitioned space existed at the end of the selected partition. If this is not the case and free space exist somewhere else, the partition will need to be manipulated with a Disk Partitioning utility.