..."may run on a Mac" is correct.
More precisely any version of windows runs more reliably on a Mac with either VMware or Parallels then on raw hardware.
See my previous post comparing VirtualBox, VMware, Parallels.
Another popular choice at universities is CentOS with KVM. A single MacPro can service up to about 100 MS/Window guests.
Operating System Choices:
Avoid Windows 7 unless you really need it.
Win7 is bloatware.
Win7 has SERIOUS licensing annoyances.
Basically, you are not allowed to move, delete or reconfigure Win7.
Win7 detects the number of virtual CPU assignments, virtual devices, and disables your Windows account in case you bump your CPUs from 2 to 4 or change from SATA to virtual SCSI drivers, etc. Not nice!
The whole idea of a Virtual Appliance is to use them and trash them and to clone new ones. Use WindowsXP SP3.
XP lacks anti-cloning features, so you can clone and trash as many copies of fully configured machines that you may so desire.
L