Why does my laptop sometimes restart when I try logging in? It sometimes hangs as well.
My laptop is running Windows 8.
This issue could be caused by the 'Hybrid Shutdown' feature in Windows 8, which shortens the start-up time, where the system is not closed but goes into Hibernation mode.
If your system restarts or shuts down during login in Windows 8, you could try disabling this feature and do a complete Shutdown.
To disable this feature,
Type Power when you are on a new Start Screen or if you are on Desktop, move the cursor to the top right corner of the screen to get to a new Charms Bar and click on Search and type Power.
Click on Settings (found in the right sidebar of the Search results).
Click on Change what the Power Buttons Do link to launch Power Options.
You can also access Power Options by typing powercfg.cpl in the RUN dialog box
Scroll to the bottom and look for the Turn on fast startup(recommended) option.
Now scroll down to the bottom and uncheck the "Turn on fast startup (recommended)" option.
If the option is not available, scroll up and click on Change Settings that are currently unavailable
Save your changes. Restart.
You can also try to execute the following command in Command Prompt. Right click on the bottom left corner of your screen to open Command Prompt and select YES for the bcdedit /set disabledynamictick option.