I'm not sure "Have you tried rebooting" in a Windows environment gets you voted into the PC support hall of fame.
Though I admit I had to do exactly the same thing this weekend with a USB flash card reader that wouldn't fly.
I occasionally forget there are "users" out there that have forgotten or weren't around in the Win9x days when that was the solution for everything and that XP and Vista occasionally need a restart too. (The second "o" in too is dedicated to Scott who provides us wih this great forum.).