2. The computer can't be turned on, which usually means that it can be turned on (the power indicator is on), the display screen doesn't display, or it doesn't respond when it is turned on. In this case, the system startup menu cannot be opened;
3. When the post can't be done, naturally don't talk about bringing up the startup menu. At this time, it is necessary to check the hardware problems, let the computer display the self-check interface, and prescribe the right medicine according to the device name and fault reason prompted on the screen;
4. If the POST passes, even if the system can't start normally, prompts such as system repair will appear on the screen in most cases. In this case, the fastest and most thorough solution is to reinstall the operating system. The reason is that if the old system on the hard disk is seriously ill, the repair will inevitably leave sequelae.