I certainly wouldn't reinstall windows because of a sound problem!
As it's a laptop, I'm guessing it has onboard sound as opposed to a separate soundcard, so my guess is you could download the correct drivers from the Toshiba website. If that driver package is an executable file, then run it after dowbload. If not, go to device manager, right click on the sound device and update the driver using the choose a specific location option.
If that fails, then at the top of the device manager, right click on your computer name and click on scan for hardware changes. If that fails, uninstall your sound device & do the hardware scan again.