I would like to have one Windows install on my mac, but the option to dual boot into it (for more intensive use) or boot it up using virtualization software (for less intensive use). I recall one of the virtualization products allowed this a while ago, but haven't kept up with the different options/features that the different programs have. What options are there for doing this? How well does it work in practice? Are there issues with Windows complaining that it is not registered/activated as a result of switching back and forth, driver issues, or any other type of problems which keep it from working as smoothly as it should?