Try opening a command prompt and type the following:
shutdown /t 0
This should force the system to shut down, as well as force any open applications to close with no timeout. The command that is run when you use the Settings menu on the Charms bar is basically the same, but a brief timeout is given in case you forgot to save and close something.
If that still doesn't work, we will need to start looking through the Event Viewer to see what is causing the problem.
I have windows 8 pro 64bit. Though i have a nice pc, windows 8 shows many issues like - when it opens the start menu goes black and then i have to restart and it starts normally, it lags for 5min while loading the icons and other stuff when i click desktop button on start menu and after that it starts working normally...
I have updated win8 with new updates...is there any problem in the new update or windows 8 pro?? shuld i switch to windows 7 ultimate? Have you experienced any type of lag in win8?