When you reach 80% of the Virtual Disk space, you’re needed to extend the Virtual Disk in Windows Virtual Machine .
This is how you do that:
First, you need to open VMware vSphere Client then edit settings of the virtual machine.
Choose the disk that you want to extend, let say the you have VD of 170GB and You want to increase it with more 30GB, totally 200GB.
Change the Provisioned Size from 170GB to 200GB and click OK.
To locate the 30GB space open CMD, enter the Diskpart command.