Virtual Driver Disk (VDD) is a free utility developed by Kenji Kato, one of unofficial VMware supporters that answers on newsgroups.
VDD permits you to mount a virtual disk and see it as a physical disk on any physical machine you want, reading, writing, etc any file inside it.
From 3.0 release notes:
Now you can use up to 22 virtual disk drives at the same time. You can increase/decrease the number of drivers while the driver is running.
New “write-block” virtual disk open mode. In this mode, the virtual disk appears to be writable to the OS, but every write command is silently ignored and data is not actually written to the image file.
Now you can use raw sector image devided into multiple files. This is in effect the same thing as VMware 2.x Plain Disk or VMware 4.x Flat Virtual Disk, but with a very simple list of component files as the descriptor file.
Now you can see the partition structure of a disk image without actually opening it as a virtual disk.