Convert fixed and dynamically expanding virtual disk images

In Microsoft Virtual PC, you can create two types of virtual hard disk images: dynamically expanding and fixed-size virtual hard disk images. You can convert one type of virtual hard disk image to the other — fixed-size format to a dynamically expanding hard disk or a dynamically expanding hard disk to fixed-size format.

Dynamically expanding virtual hard disk images Expand to a specified maximize size as more files are added. However, dynamically expanding virtual hard disk images do not automatically shrink as files are deleted. To reclaim this space, you must first use a third-party software product to "zero out" or permanently remove data from the virtual hard disk image.

Fixed-size virtual hard disk images Remain the same size, regardless of the number of files that are added to or removed from it.

Make sure the virtual machine whose virtual hard disk image you want to change is shut down completely. In Virtual PC List, the status of the virtual machine must be "Not Running".
If it is not shut down completely, start the virtual machine. In Virtual PC, on the PC menu, click Shut Down. Click the Shut down option, and then click the Shut Down button.
On the Window menu, click Virtual Disk Assistant.
Click Examine or modify existing hard disk image, and then click Next.
Click Select a hard disk image attached to a PC, and then click Next.
In the PC box, select the virtual machine associated with the virtual hard disk image that you want to modify.
In the Disk box, select the virtual hard disk image that you want to modify, and then click Next.
To convert the disk image, click Next.
Click Convert, and then click Done.

See also

About reclaiming free disk space

Reclaim free disk space