Realtek Audio problem
Did you install the Reliable driver from the
Dell – Support Downloads webpage for your Tag Number, not model number? This customizes the driver choices for your exact PC build.
There may also be a driver controlling the on-screen Book and function keys that needs install. If you’ll report back your Tag number we can help you search for it and anything else that might still be needed.
Did you follow the steps here in
Clean Install Windows 10 which compiles the best install of Windows one can have and has zero issues reported by tens of thousands of users?
Windows 10 Performance and Install Integrity Checklist to check that the install is set up correctly, optimized for best performance, and do any needed repairs.