I had upgraded my computer from Windows XP to Windows Vista. I had installed the operating system from my Ts-H492c DVD drive. But due to some reason I had install everything back again. The problem is that I cannot boot from DVD. The Vista Setup Menu at the boot up does not appear. My BIOS shows up that boot from cd/dvd. By press space nothing happens. Neither the DVD drive is reading other disc. Any suggestion really appreciated. Thanks.