I am using Window Vista on my computer and I have used the backup feature of this same operating system to backup some data on my external hard drive. It went smoothly and everything was copied but when I tried to safely remove the same drive then it was giving me some message - " Windows can't stop your Generic volume device because it is in use. Close any programs or windows that might be using the device, and then try again later". I have checked that everything was closed and ensure in task manager that this hard drive was not using any process. After about an hour or so, I was finally able to unplug it safely? So, i was wondering what could be the problem here?