I am willing to do another install of Vista
Before you do that I suggest the following.
Certainly for some hardware, like HP Printers, it is essential to not
have the printer or its cable connected to the PC until either the
software installation tells you to do so or until after installation of
software is finished.
Then you can plug in the device and its cable and turn it on and let
Windows detect it. So check carefully the instructions that come with
the device and also check the manufacturer's web site for updated
versions, workarounds and advice.
I do support over on Compuserve and time and time again we see this
problem occur when people do what seems natural and set up the printer
and then install the software.
So try this:
(1) Turn off and unplug the printer (let's stick to that device)
(2) Go to the Printers part of Control panel and delete the icon for
the printer.
(3) Go to Add/Remove Programs (I think it's called Programs and
Features now) and Remove any programs related to the printer
(4) Go to Device Manager and Remove the entries for the Enhanced USB
controller(s) and any reference to the Printer if it is there (my
PS8250 dot prot shows there)
(5) Then reboot the PC and let VISTA detect the USB controllers again
(this may not be necessary so if you want you can skip it and only do
it if you have USB trouble afterwards)
(6) Then install the software for your printer and attach the printer
when told to or when the installation is finished.
I hope that helps. I have not done Step (4) in VISTA but I have done it
in XP and see no reason why it should not work, but I don't know what
VISTA protection allows you to do! There's always Run As Administrator!
If you care to tell me the exact make and model of the printer I may
have some more advice.
Good luck.