Hi, My HP Envy, 64-bit Win 10 fast version, will not start into windows. It sits and those little dots spin for hours - overnight, with the words "Diagnosing your computer" doing nothing. I need help getting into Safe Mode, from a powered off PC. It just spent more than 13 hours with the dot-circle spinning from a power off state, and nothing else happened. I have a flash drive with an older Norton recovery disk on it, but not sure which version of Win is on it, 8 or 10. I also have an old - first build - of Win 8 on a flash drive, and am willing to use it to boot up, if it will not ruin everything. I just want to get to Safe Mode to use System Restore and go back two days or so. If anyone can tell me how to get to Safe Mode from a Powered off state, I'd appreciate it. Thanks again, everyone, -a.