To increase the disk size of a Windows Server 2012 virtual machine follow the instruction
- Increase the disk size in the properties of the virtual machine in accordance with the article.
- At the operating system level - run "Computer Management" from the "Tools" menu of Server Manager.
- In the "Computer Management" panel, right-click on the expandable section, select "Expand Volume".
- In the wizard that appears, click "Next", "Next", "Finish."