I ran Tweaking to repair a system which sfc and standard dism, chkdsk etc found no problems with but which kept randomly rebooting of turning off all output to the monitor. Now, I can't set default programs, (among other settings that I can no longer change either in the new Windows 10 settings or traditional control panel - I click a choice but nothing happens, and my choices are ignored. It appears you somehow set permissions to all these settings so that I, as Administrator cannot set them.
Further, the advent of a random restarts / black screens comes quicker and in larger number after the so-called "repair".
I'd love to look at the event log, services app, dcomcnfig etc. but attempting to run any of those apps crashes the machine almost immediately. And yes, I started from step on, and did all the optional steps before repair. What a wast of 6 hours.
BTW, I tried to restore both the registry and to the restore point I created before I ran this sorry utility, and guess what - THE SYSTEM TELLS ME THERE ARE NO BACKUPS OR RESTORE POINTS TO USE TO GET BACK TO WHERE I WAS BEFORE THIS PIECE OF POOP SCRAMBLED MY OS!!
Thanks! Now I have no choice but to wipe the HD and start rebuilding from scratch - a process that will likely take two months to complete.