Tout est dans le read me :
The Virtual PC for OS X Test Drive is Beta software, and there are some features that are not currently available when compared to Virtual PC 4.0 for Mac OS 9. Some of the major differences are:
- No USB support. USB devices cannot be used with the Virtual PC for OS X Test Drive. However, mice and keyboards connected to the Mac for normal functionality are utilized in the Virtual PC for OS X Test Drive.
- No full-screen mode support. 
- Limited networking. Unique IP is not available. Shared IP can be used with some limitations: Users can logon to a domain, browse the web and FTP files but will not be able to browse a network using Network Neighborhood in Windows.
- No COM or Serial port support (modems or other devices cannot be mapped to a COM port in a guest OS.)
- Limited drag-and-drop support: Dragging an item from a Windows OS to the Mac will not function. You may still drag files into Windows from the Mac desktop provided the Windows OS you are using has the latest version of the Virtual PC Additions installed. The Virtual PC Additions can be obtained from
http://www.connectix.com/support/vpc_additions.html