Have ye perhaps got a USB hub in the circuit? Some of they aren't quite up with the ferrets when it comes to performance.
new-build PC should be all USB2.0 . I'd be pretty miffed if anything bought in the last two years were anything less.
Anything that wants a driver gets a copy stuffed into the Win/System32/Drivers folder. If it complains, it gets told to look in there. After a while, it takes the hint and stops bothering me.