1. Right click on 'Computer' then click on 'Manage'.
2. Once in the Management Console, simply click on 'Disk Management' located in the left hand tree directory.
3. You will see your default 10GB primary partition at this time. Simply right click on the partition and choose 'Extend Volume'. Simply follow the on-screen wizard.
You can also choose to expand your partition by right clicking on the unpartitioned space and creating a new partition. However, we do not recommend this as a 10GB primary OS partition may cause issues down the line with limited disk space to utilize.