Dawn and Nick

Hi
My canon printer was working perfect, I have a laptop with Windows Vista. I also loaded Microsoft XP, on, but it messed around with my email so I removed it. My printer often came up with the message that there is an unknown device plugged into USB. I was informed to remove the printer and reinstall, however when plugginf USB back into laptop, it now comes up with USB Device not recognised, and will not auto run, also when I attempted to print, it will say device not found. Please help me. What can I do to get the printer running. I am not a computer whizz, so please laymens terms. Thanks, Dawn