Windows 10 PC Troubleshooting and File Recovery

I am seeking a skilled technician to help resolve issues with my Windows 10 home edition PC. The tasks include recovering lost files from the C: drive, fixing audio and speech problems, and fix the image problems (the images can be viewed by right-click and choosing: use the "photo" to edit, but if left-click, it asked you to open the app "ms-paint"). The ideal candidate should have a strong background in Windows operating systems and troubleshooting. If you are experienced in file recovery, audio settings, and general PC maintenance, I would love to hear from you.

I'm using windows 10 (home edition), it seemed that it was updated suddenly without my notification. Then I found my old files which were saved on desktop only disappeared. Some of my software that I previously using were also disappeared. There are no folder named "temp", "windows.old", etc. I also restarted my pc more than 5 times. I reinstalled the 3 drivers in order to fix the sound problems. I also searched on file explorer to check my documents, still can't find them. But all issues are not fixed yet.

You will be asked to answer the following questions when submitting a proposal:
1) Describe how you would help me in this project. Please specific the steps you would take action to.
2) How much time do you think you will need on this project?
3) Please state the payment for:
1. a milestone of each (speech and audio; files recovery in c drive) and
2. all-in-one
4) Describe your recent experience with similar projects
5) Please list any certifications related to this project