Build in speakers and microphone not recognized.

Hello, I have an Alienware M14x R2 and for some reason, my computer isn't playing sound and it says there is no speaker or microphone connected even though they are built in.  In system preferences, it says no audio devices are installed.  The driver is supposed to be the creative sound blaster one, which is installed, however in device manager it does not show up in sound.   All my drivers are installed and up to date and I did not have this problem before today.  Please help me solve this problem.