Assuming you have tried all the ports on your computer, do you have another
enclosure that does work? If you are using a pci card for your usb ports,
have you tried moving it to another slot?
In any case, be sure to tell MS via the feedback link.
I was able to get my usb scanner drivers loaded after turning off the UAC and
exploring the driver CD and setting all properties to run in XP SP2 mode
before running setup,exe file but it did not help with printer drivers.