I think that you mentioned that in the sound & audio devices its all gray , so try this it will help you:
Go to
Start menu and chose
Run, write this command:
services.msc, press enter
In new window on the right panel find
Windows Audio and double click on it, when you see the new window under
Windows Audio Properties in page
General down to the
Startup type make shore it is
Automatic and in the part
Services status click on
Start than
Apply,
OK and the problem is solved.
I suggest you this because sometimes this service is stoped by some virus infections, even if your PC is protected by antivirus software, when you delete the virus it leaves this problem.
P.S. Let us know if this did helped you.
Cheers.