A VMDK file is a virtual hard disk file created with virtual machine software from VMware, Inc. A virtual machine is a computer emulation on which you can install an operating system separate from your computer. Virtual machines are typically used to run legacy software, meaning software that cannot be run on newer computers. Each virtual machine requires a virtual hard disk, which functions much the same as a physical hard drive from within the virtual machine. To create a VMDK file, you'll need to create a new virtual machine.
Download and install "VMware Workstation" from the VMware website.
Launch the VMware Workstation program by double-clicking the desktop icon or clicking the shortcut from the "All Programs" list in the "Start" menu.
Click the "File" menu.
Click "New" and "Virtual Machine." Click "Next."
Click to select "Custom" from the "Select the Appropriate Configuration" options, then click "Next."
Click to select the operating system that you intend to install on the virtual machine from the listed options. Click to select an operating system version from the "Version" drop-down list, then click "Next."
Type a name for your virtual machine in the "Virtual machine name" text field. Type a save location in the "Location" text field, or click "Browse" and select a save location for the virtual machine files (not including the VMDK file), then click "OK." Click "Next."
Click to select the number of processors to use on the virtual machine. The "two" option is only available if your physical computer has at least two processor chips. Click "Next."
Click and drag the slider to allocate physical memory (RAM) on your computer to the virtual machine, then click "Next."
Click to select a network connection option from the available list based on how you want the virtual machine to connect to your network. Click "Next."
Click to select the SCSI adapter type for the virtual machine. If unsure, leave the "Buslogic" SCSI adapter type selected as default, then click "Next."
Click to select "Create a new disk" in the "Disk" options menu. This option creates the VMDK file.
Click to select the "IDE" or "SCSI" disk type, then click "Next."
Type a disk size in gigabytes in the "Disk size" text field. This option determines how much disk space the VMDK file will require.
Click to place a check in the "Allocate all disk space now" to reserve the physical disk space for the VMDK file immediately. Click "Next."
Type a file name for the VMDK file in the "Disk File" text field. Click browse to select a save location for the VMDK file, then click "OK." Click "Next."
Click "Finish" to create the virtual machine and the VMDK virtual machine hard disk file. The VMDK file will be stored in the save location specified in the previous step.