99% of the time it's either #1 Microphone not plugged in or bad wire on the Microphone. Or a USB Mic/Headphone issue.
If you have a USB headset and/or Mic make sure that you plug it into 1 of the USB ports on the back of the PC. The USB headers on the front of the case are usually set to Lower priority and can cause issues when used with headphones and/or Mic.
USB thumb drives will often not be detected or will not boot off of the front panel USB ports on alot of PCs. This tells me that they are either not initiated fully at boot or are set to lower priority.
Never EVER update your Sound drivers if they are working especially with the Realtek sound and LAN drivers.
If you have to install or update a Realtek driver, get the latest one that was Made for your motherboard from your motherboards Manufacturers web site. It might be a couple of years old but it was Made for your motherboard.
If you make the mistake of installing a newer one from Realteks site and it doesn't work? You will most likely have to reinstall windows to fix it because it over writes the default windows drivers which are not saved when you make a restore point.
I am sure that there is a way to get around this but, it will not let you install an older driver Because that fucked up realtek driver is "newer" than the one that you want to install.