Hello. I have never used the program "TuneUp Utilities", so that part was inapplicable to me. The Microsoft Software Shadow Copy Provider service was set to Manual and was not running, so I started it and set its startup type to Automatic. However, even after doing this, I still got the same 0x81000203 error when opening System Restore. Finally, I checked the Group Policy entry for "Disable System Restore" and it was already set to Not Configured, so that part was also inapplicable. So in summary, none of the steps from the link you gave have solved the problem.