There are a 2 things I can think of that could cause freezes.
Problems with system files, like corruption or missing files
Failing hard drive
Please open an admin command prompt (right click left corner in the bottom > command prompt (admin)) and copy/paste "sfc/scannow" (without quotes)
Let me know the result.
For the problem with the sound I need your system specs
Please fill in your system specs
Please go to this site
and download the tool. The tool will give you detailed information about your system specs, please fill in your system specs more completely.
How to fill in your system specs: