It should have shut down!? If you have trouble turning on the computer suddenly, check the settings first.


It ’s been about a month ago. A computer that should have been shut down may have started up by itself. At first, I thought that I had accidentally selected restart, or that my child pressed the power switch. Recently, the power was turned on about 15 minutes after the shutdown.

Despite selecting “Shutdown” instead of “Standby”, “Sleep”, or “Restart”, the computer power switch was turned on when I noticed.


What is the cause?

Even if I wanted to investigate the cause, there were power buttons, power supply units, and motherboards as possible parts. It is difficult to judge that any part is “broken” from the appearance. It takes time to check again. For the time being, I decided to review it from the settings.

The Windows 7 that you are using has a “Wakeup on LAN” function, and it seems that you can turn on the computer with a signal from the LAN cable. (After moving home, the Internet environment changed and the phenomenon of turning on the power began to appear.)

Press the start button of the Windows logo,
→ Control panel
→ Device manager
→ Network adapter
→ Right-click the adapter you are using to open the properties.
In the “Advanced Settings” list,
・ “Wake on Magic Packet”
・ Wake on Settings
・ Wake On Setting
・ “Wake-On-Lan function”
・ “Wake-up function”
・ Wake on Magic Packet
Select “Disable”, “Off”, “Off”, or “Disenable” for the settings of these items and press the OK button to complete. With this setting, the computer will no longer start up by itself.

The first thing to do when trouble is checking the settings

It seems that the PC may mistakenly detect signals such as noise from the LAN cable and turn on the power without permission. If the power still turns on even after changing to this setting, you may need to review the BIOS settings, but first try disabling this wake-up function and see how it looks .