I believe it was Workstation that initially created a 40GB disk partition for the VM when I created it and it had stuck ever since.
Recently that Windows VM, used as my desktop (which was brought over from VMware Fusion and Workstation before that) ran out of disk space. It is there that I run Outlook 2010, run the vSphere Client (as it only runs in Windows, and any other Windows apps I need to run (as my new primary desktop is a Macbook Pro laptop connected to a Thunderbolt display). I used a vSphere VM as my primary Windows desktop (when I use Windows, that is).
