My computer keeps shutting down instantly when I'm in Windows – as if you pulled the power cord. There's no bluescreen or anything like that. Then, it starts up again. This happens at random after around 5-60 minutes of uptime.
If I enter BIOS setup, I can leave the computer running for days without this problem. That shows that my hardware should still be ok.
Where would I start troubleshooting? The event log looks good, and since there is no bluescreen, there are no other error messages to go after. It's like the power is cut off instantly, and then the computer just reboots itself.