There are many instances of people installing new scanners and printers on new systems using USB 2, and having "Not Responding" errors. The USB 1 ports are having less instances of this problem.
The described problem can be very frustrating, and sometimes be very difficult to resolve. Many users would first start by uninstalling and reinstalling the software, when the software is not directly at fault.
At the hardware level, and at the Windows test level, the device checks to be okay, and responding properly. Yet, it does not respond properly when doing its work.
Some symptoms are that the scanner may stop in the middle of the scan and hang, or not scan at all. Or, a printer may stop in the middle of a page and hang. In the case of the printer, if it does not hang, it may start to print random looking characters during the middle of a print job.
It turns out that with USB 2 ports, on many P4 machines this problem may occur with some scanners and printers. This has to do with several factors.
If the USB Root Hub is IRQ shared with other devices that are particularly active, this problem may occur in many systems. This has to do with data streaming being interrupted (shared IRQ requests), and the receiving device becoming timed out. The device becomes out of sync. The device may then hang, or stop responding, and have to be reset.
There is also the condition where the data inputs of the device being driven by the USB port are pulling peaks of too much peak current for the USB port to handle. Considering the speed of the data coming from the port, the effective impedance of the device load may be a bit low, thus causing it to pull more current than what the USB port can support.