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im having trouble installing the usb i need some help , please understand im very new at all this thanks,
i have taken two screen shots if this helps on is a error the other is what i pressumed i need to have to make the usb work .

it appears its trying to register on the virtual box but i occasionaly get this error .

any help i would appreciate thanks

I use Win7, not Vista, and I have the same troubles which are fixed just by shutting down guest, then rebooting host.
Please note that you are likely to get the same error and need to reboot the system when either you change physical device (in case you have more than one) or you change USB port.