After reinstalling windows 7, my pc wouldn't detect my sound card, it gave the message -No Output Device is Installed-. I tried everything. Downloaded drivers directly from the Toshiba website and also from Realtek. None of that worked. Finally I went to the bios and I resetted to the factory settings.
Somehow, after restarting the computer, windows finally found the card. The only thing i had differently was the booting order. First I had the CD and then the hard drive.
By default, it its the other way around. It doesnt makes no sense, but that finally fixed my computer.
Good luck with your computer.