Hi, I have WinXP machine (not the one you see on the bottom) in very good condition. Newer PSU with sufficient wattage, yet I cant run more that 1 USB device (no hubs). I have my printer connected in, but if I plug in as flash drive, scanner, or a hard drive none come as "recognized." If I kick out the printer I can work the other one and only one. The USB ports are all fine and so are the devices. What do I do?