Solution to Error 1327: Invalid Drive

I was migrating a Parallels virtual machine to VMWare Fusion. After importing the VM and starting it, I tried to install VMWare Tools but repeatedly got the message Error 1327: Invalid Drive Z.

It turns out that as part of its OS X integration Parallels writes entries to the registry.

The solution was to type regedit at the Windows command line and use it to remove any entries at

HKEY_CURRENT_USER/Software/Microsoft/Windows/CurrentVersion/Explorer/User Shell Folders

that began with Z:. After that, everything was happy.