Trying to determine the crash cause
A system crash can be due to two basic factors. One reason is that your computer will not boot due to a hardware failure. The second reason is that the operating system is corrupted and Windows will not start up.
In the first scenario, it is better to let your service center handle the repairs. However, you may want to perform some routine tests. Check the cables, connectors, power of external devices, etc. Then, restart the computer. The POST (power-on self test) that starts immediately after you turn on your computer, checks your system hardware. If the POST has found a failure, you will need to send the PC for repairs.
If the POST does not reveal a hardware failure, enter BIOS and check whether it recognizes your system hard disk drive. To enter BIOS, press the required key combination (Del, F1, Ctrl+Alt+Esc, Ctrl+Esc, or some other, depending on your BIOS) during the POST sequence. Usually the message with the required key combination is displayed during the startup test. Pressing this combination takes you to the setup menu. Go to the hard disk autodetection utility which usually comes under “Standard CMOS Setup” or “Advanced CMOS setup”. If the utility does not detect the system drive, it has failed and you need to replace the drive.
If the utility correctly detects your system hard disk drive, then the cause of the crash is probably a virus, malware or corruption of a system file required for booting.
If the system drive is healthy, try to recover the system using a backup of your system disk or system partition. Because Windows does not boot, you will have to use Acronis bootable rescue media.
You will also need to use a system disk backup when recovering the system after replacing the damaged hard disk drive.