How to get a vmdk mapped in Windows Explorer when using VMWare Player 4.x and Windows 7

VMWare... Yet another textbook story of a technological company that has become a bit too complacent with its users, possibly without even realizing it (Disclaimer: I have been a virtualization evangelist, as well as direct contributor to sales of VMWare products in the previous company I worked for, so I do feel somewhat entitled to exert criticism).

So, you have VMWare Player 4.x, installed on a Windows7 platform, and let's say you fancy recompiling FreeDOS in a virtualized environment. For this you have set up your VM, with a small virtual disk and everything, but since it's DOS, no shared folders or VMWare Tools will be available there. Yet you need a solution to exchange data in a convenient manner, between the Windows 7 host and the VM disk image. How are you going to do it then? Why, by mounting the vmdk as a virtual drive of course. And since VMWare is a Virtual hardware company, they made sure that such a staple of virtualization was as easy and as straightforward as possible, right?

Wrong. Below is what you actually need to go through:

1. The VMWare Player does not natively offer any tools to map/mount a virtual drive. You have to install extra software.
2. That software is the Virtual Disk Development Kit (presently in its version 5.5.1) which can be obtained here (after registration of course! It's not like you were about to sort this virtual disk mapping issue in 30 seconds anyway).
3. Once installed (by running bin\vstor2install.bat), and of course without any obvious mention of it (since officially it's an SDK, not an application plugin!), you will find out that the following becomes available when editing your disk properties:
   
   Brilliant: a GUI with the ability to map drives is exactly what we've been looking for.
4. Except, at least in Windows 7 x64, and if you run VMWare Player 4.x under your regular credentials, you will be greeted with the following error message "Error reading volume information. Please select another disk file":
   
   Same occurs if you try the vmware-mount.exe from from the VDK's bin directory (and this even if you open a command prompt as admin, as I have also found)
5. To avoid the "Error reading volume information..." message then, and be able to mount the disk, you must run VMWare Player as admin
6. HOWEVER, "Open drive in Windows Explorer after mapping" still will not work, because Explorer is running under your user credentials, and the drive was mounted under the Administrator's credentials. Thus, you must run your File Explorer as administrative.
7. Luckily, if you happen to run a proper File Manager (such as the most excellent Directory Opus, which I can't recommend enough as it's well worth its license), this isn't a major problem and you will actually get the friggin' vmdk mapped at long last, with the ability to transfer files. If you're stuck with the default Windows Explorer, running it as admin may or may not work —can't test, as on my machine, Directory Opus is the explorer that will be launched by default by VMWare)

Yay, at last VMWare may actually prove useful in getting some work done. Now let's see if the FreeDOS guys also see it this way...

Update (2012.01.06): The FreeDOS people kindly indicated that vmsmount might also be able to help you out if you want to acces VMWare shares from DOS.