After leaving the computer idle for some time, like overnight, I find the computer apparently awake (sleep light not on), with the hard drive light irregularly but dimly flashing, and no way to access it. Neither mouse clicks nor any key on the keyboard does anything, nor is there any apparent reaction to those actions in terms of the hard drive light. The only way to resolve the issue is to press the off button until the computer shuts down, take out the power cord until the little light on the back goes out, and then insert the power cord and restart. After that, all is good. I am running Windows 10, set to go to sleep after 20 minutes of inactivity. This seems fine during the day, when I am not away for lots of hours. The computer goes to sleep but wakes up fine. Is this a Windows issue, or something to do with the BIOS, or something wrong with the computer? Is there a way to recover information on what was going on when the computer froze? Thanks!