Had this PC for a few years and decided to do a bit of an upgrade.
It was running 2GB of Ram and a standard hard drive. I've added an extra 4GB of Ram and a 250GB SSD.

After installing windows 10 I've noticed that every second boot the PC will switch itself off when it gets to the windows boot screen.
So it goes regular as clockwork, switch on PC get to the windows logo screen, PC switches off. Switch on PC again and Windows starts without any issues and the PC works as normal.

Anyone have any ideas??

Ta.

Not related, but is it a 32 or 64 bit system?

64 bit.

In the meantime I have gone back to my original memory in their old configuration and the problem persists. Tries all different combinations of the 4 sticks of memory and the problem persists.

The new memory is the same speed as the old ie DDR2 800MHz.

I'm now looking at resetting the CMOS to see if this will help.

[Edited on 9/8/15 by cerbera]

[Edited on 9/8/15 by cerbera]

To me it sounds like a failed Windows update that keeps getting retried. Windows 10 is delivered with automatic update active unless you switch it off.

CMOS reset did nowt.

You may be able to see whats causing it in the Event Viewer.

Start the PC up, take a note of the time and let it switch off doing what its doing then wait a few minutes so that you have a good reference point in the event logs to scroll back and find. If a driver or something is causing it it may be in there and give you a clue.

Cheers
Stot

Just thought I'd post that I fixed it in case anyone else has similar issues.

When I installed the SSD I should have gone into the bios and changed the SATA type from IDE to AHCI prior to installing windows.
Perhaps this is just peculiar to my motherboard, and maybe new ones will do it automatically.

Anyway, had to do another clean install of Windows 10 but made sure of this setting first. Now I don't have the strange boot issues.

This can also be caused by the fast boot setting in power management. I had it happen on every first boot when I upgraded to 8.1. Fixed it by disabling fast boot but it reared its head again when I upgraded the same machine to 10. Lo and behold the default Win 10 fast boot setting is on.
I think it's caused by some motherboard power management settings not being compatible with Win 8.1 and upwards. Changing to AHCI would alter that, disabling fast boot bypasses it.

Steve