Windows is zo langzamerhand niet meer m'n sterkste kant maar het volgende haal ik uit de VB handleiding voor Vista guests (waar die driver dus ook ontbreekt):
Windows Vista no longer ships a driver for the AMD PCnet Ethernet card that VirtualBox provides to the guest by default (see Section 6.1, “Virtual networking hardware� ). As a result, after installation of Vista in a virtual machine, there will be no networking initially.
As a convenience, VirtualBox ships with a 32-bit driver for the AMD PCnet card, which comes with the Windows Guest Additions. If you install these in a 32-bit Vista guest, the driver will automatically be installed as well. If, for some reason, you would like to install the driver manually, you can find it on the Guest Additions ISO. To install this driver, mount the Guest Additions ISO (as described above, select "Install guest additions" from the "Devices" menu). Then, start the Windows Hardware Wizard and direct it to the Guest Additions CD where a driver for the PCnet card can be found in the directory 32bit\Windows\3rdParty\AMD_PCnet.
Alternatively, change the Vista guest's VM settings to use an Intel networking card instead of the default AMD PCnet card; see Section 3.7.5, “Network settings� for details.
Lees voor "Vista" "XP" en mogelijk lost het jouw probleem in XP dan op.
Gr,
Jim
