I tried creating a VM out of a Vista tower using free VMWare vCenter Converter Standalone to do it and it was a successful VM, with one exception: I could not get the VM to recognize an internet connection, and I tried that both on a Windows 8 machine running free VMWare Player as well as on a new MBP running Fusion 6, Mavericks. Neither worked. But I still had a license from an older Boot Camp installation of Vista and, while I didn't have a working DVD drive, I was able to download and create an .ISO...basically, I created a new VM with a new install of Vista and simply imported documents onto it from the old Vista tower as well as downloaded/installed applications as needed/desired. It may be a few more steps, but it may get you to "a" solution (maybe not "the" solution you wanted) more quickly. I found that I was able to get the desired networking working in both a Fusion (Mac) and VMWare Player (Win8) environments.
You will need to address Vista licensing, of course.
If you need help locating downloads to create a Vista .ISO (it takes a few steps as it comes in three files and requires a third app to create the .ISO in Windows), I can help. Thanks to WoodyZ for the help in getting me started on that Vista project.
Message was edited by: Coach300 regarding licensing.