I have a problem with my USB ports, both back and front. If I have the printer connected, and switch it on, the pc shuts down, and tries to re-start. If I plug a USB memory stick directly into the pc, it shuts down. If I plug the memory stick into a USB extension lead, the pc reads the content. If I plug a web-cam in directly, no problem. I have fitted a PCI USB card, did not help. I have fitted a higher rated power supply, did not help. Any ideas please, as I am getting very frustrated. Cheers, nsdancer.