A month ago I purchsed an arduino uno. I used on a windows 7 and it worked properly. I now am trying to get it to work with a windows XP. When I look under device manager, the uno is under the other devices tab (will not show tab if you don't have any unknown devices) , not the ports and coms tab. Any suggestions?
Thanks, qtechknow 
Have you installed drivers for it?
I think it works now. Thanks!