I have an HP Pavilion ze5400 Notebook, it is currently running Windows XP SP2 and it doesnt recognize any USB device that I plug into it. I have tried several different devices and devices that used to work with the computer. This problem occurred when I upgraded from XP SP1 to SP2. Just as a test I removed SP2 and brought the computer up running with XP SP1 and all of the USB devices worked fine. I have since put XP SP2 back on the computer and none of the USB devices are recognized. Any ideas?