A few days ago I started getting that message. Was doing nothing unusual, AFAIK. This computer runs Win 7 64 bit, UEFI & GPT hdd, avast free, Shadow Defender, Macrium paid with the boot option enabled. The computer will boot into safe mode. System restore doesn't work, shows that there are no restore points. But there were some before this started. There are many mentions of this issue on the net, including some on this forum. I found instructions for going in to safe mode & using regedit to rename the user profiles by changing the .bak extensions. That seems easiest if it actually works. Has anybody done it? Is there an easier way? Thanks for any suggestions.