USB Hub - Unknown device

I am using a USB hub here. I am having a Windows XP PC. On that hub I had already attach a printer, hard drive and ipod on the same. It was working fine. But somehow it stopped working on its own. When I try to connect a usb drive I am getting unknown device error. The hub just stopped working on its own. I am getting windows does not recognize the device. The hub is just purchased a couple of months before and not it stopped working. Can anyone guide me here for the same.

Try to update the drivers and then test back. First disconnect all the connected devices. Then go in device manager and update the drivers. If it still does not work then it is a hardware fault. You can also try changing the usb port and see what response you get. My old hub had also stopped working in the same. But I bought a new one. It is relatively cheap.