So, when you restart the PC, it just hangs and nothing happens? Any problems when you power on the PC? Are there any performance issues?
Please boot in Safe Mode and check if the restarting problem persists. You have done pretty good job trying to solve the issue. It may be worth it to do a fresh Windows installation. This way we may exclude a software issue as part of the problem. Before reinstalling, make sure you have backed up all important data.
Hope this helps