It would probably not be a SoundBlaster, but "compatible" with it.

Down at the bottom of the screen, do you show a task-bar? On the right hand side, is there a speaker shown? If there is, click on it. Now click on the top left under Options. Then Click on Properties. IT should show either Recording or Playback Checked off. Just below that you should see a number items Checked off or NOT Checked Off. Make sure all items are checked off. Try that next. It could be that something isn't turned on.