I recently upgraded from Win 7 to Win10. The upgrade went smoothly with one big exception: after I boot Win 10 it inevitably crashes a day or two later with the dreaded "BootMgr is missing Press Ctrl-Alt-Del to restart" error message. To be clear, Win 10 starts and runs fine for a day or so and then crashes. Each time I have to restart Win10 with the start button on my computer, and lo and behold Win10 starts normally. I did not have this problem with Win7. I tried the usual recommended fixes: startup repair from the installation disk, and CHKDSK C: /f; but nothing has worked. At one point when I booted Win10 I was assigned a temporary profile, and I had to fix that through some registry entries. That problem apparently has disappeared, but the "BootMgr Is Missing" problem persists . Any ideas or suggestions would be much appreciated.