Have you checked your audio drivers to see if they are the latest??
Go to Control Panel>System>Device Manager>Sound,etc>High Definition Audio Device>Driver>update. If the "update driver" does not work, try "roll back to previous driver" if it will let you.
If none of this works visit the manufactories site and look for updated drivers. Remember to uninstall the present drivers in Device Manager.
There are lots of posts around various forums that give suggestions.
You might check that your computer is looking at the right input jack. Right click the speaker icon and check the recording devices to see if its using the front or back jack. I had this small prob after reinstall. Quick fix, set the correct one as default