VirtualBox is brilliant. You can set up Windows XP, Ubuntu Jaunty etc and test installations into them. Then reset to snapshot and rinse and repeat. Installing onto systems that are not “clean” is never as certain – perhaps you have already installed comtypes or whatever.
One tip for sharing files between a host OS and a Linux (Ubuntu) guest OS (see http://www.virtuatopia.com/index.php/VirtualBox_Shared_Folders).
Within the guest OS, make a directory e.g.
sudo mkdir /transfer
Then mount the shared folder you set up externally in VirtualBox using:
sudo mount -t vboxsf sharename mountpoint
in my case:
sudo mount -t vboxsf transfer /transfer
It is then easy to grab files from the host OS e.g. a deb package that needs to be installed.