This is a crash when it is closed. If it doesn't happen often, press the power off button to turn it off. If it happens frequently, you can test whether the temperature of the CPU is too high. If HD is gray, another method is to reinsert the memory to clear the gray. On the system side, shut down all programs before shutting down, and what software or plug-ins were downloaded before the failure? If so, try uninstalling them. Still no, kill Troy, restore the system or reinstall it.
Use the system restore method that comes with the system:
System Restore: Start/Programs/Accessories/System Tools/System Restore, click Restore my computer to an earlier time, and then click Next. You will see that the date page has a dark date, which is the restore point. After it is selected, click Next to restore the system (Win7), and then select the device and security sub-options in the control panel.
If the shutdown problem cannot be solved temporarily, just shut down. Right-click the taskbar selection/task manager, hold down the Ctrl key, click "Shutdown"/"Shutdown" on the task manager page with the mouse, and then release the Ctrl key to wait for the shutdown.