I found a thread on the Windows Forum that matches your issue. The user in that thread had a similar problem with their computer freezing without any BSOD or crashes, especially while using the Steam client and games. They also mentioned taking various troubleshooting steps like updating BIOS and drivers, reinstalling Steam and games, setting BIOS settings to default, running tests, and cleaning the system. The user shared their detailed system specs from a Speccy report, similar to what you've done.
Since your issue aligns closely with the one in the forum thread, you may find it helpful to review the responses and solutions provided there. Additionally, I can assist you in addressing the freezing problem based on the suggestions I...