December 2016

  1. Download the SDelete program provided by Microsoft onto your Windows Guest machine.
  2. Clean up unnecessary files and programs. One useful utility is WinDirStat.
  3. Run the following command in the terminal to write zeroes over unused disk storage in your Windows guest:
    sdelete64 -z c:
  4. Shut down your VM and run the following command on your Windows Guest VDI:
    VBoxManage modifyhd /misc/virtualbox-vms/Windows10/Windows10LargeDisk.vdi
  5. Create a new VDI with the new desired maximum size:
    VBoxManage createhd --filename /misc/virtualbox-vms/Windows10/Windows10Disk.vdi --size 92160
  6. Clone the existing VDI into the newly allocated one:
    VBoxManage clonehd /misc/virtualbox-vms/Windows10/Windows10LargeDisk.vdi /misc/virtualbox-vms/Windows10/Windows10Disk.vdi --existing