My PC is plugged into a wall switched socket, so its own switch is never used. On switching on, everything lights and it starts to boot, and then it switches itself off. I restart using the reset button, and everything is OK. It has done this since it was new. Any ideas anyone?
This is normal operation. Two of my desktops do this when I turn ON the power strip that supplies power to the computers and the peripherals.
When I turn ON the power strip, the fans turn ON, and some indicator lights come ON. Then nothing happens. The system has initialized for Startup. Startup occurs when the computer Start/Reset combo switch (Dell front panel) is depressed.
If you do not want this mode of operation, leave power ON the computer after you shut down the computer using the Windows shut down sequence.
On one desktop I leave the power ON after shutdown - on the other, I turn OFF the power strip after shutdown and what you describe occurs during the next startup. This is normal.