This is a shot in the dark, but if you are somehow being denied the right to
load a driver, you might try to load it in a slightly different way.
Is this an executable application you use to load the printer driver? If
so, then instead of double-clicking it to start the operation, hold down the
shift-key and right-click the icon. Select "run as" then input your
administrator credentials. See if you get a different result.
I have had to do this since running Vista once or twice even when I was
logged on as the administrator. It's still buggy, I guess.
If this doesn't work, please provide more detail as to your loading process,
including how far the load gets prior to the error.
